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Entry version 132 (07 Apr 2021)
Sequence version 1 (01 Jun 1998)
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Phosphoserine phosphatase SerB2



Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv)
Reviewed-Annotation score:

Annotation score:5 out of 5

<p>The annotation score provides a heuristic measure of the annotation content of a UniProtKB entry or proteome. This score <strong>cannot</strong> be used as a measure of the accuracy of the annotation as we cannot define the 'correct annotation' for any given protein.<p><a href='/help/annotation_score' target='_top'>More...</a></p>
-Experimental evidence at protein leveli <p>This indicates the type of evidence that supports the existence of the protein. Note that the 'protein existence' evidence does not give information on the accuracy or correctness of the sequence(s) displayed.<p><a href='/help/protein_existence' target='_top'>More...</a></p>

<p>This section provides any useful information about the protein, mostly biological knowledge.<p><a href='/help/function_section' target='_top'>More...</a></p>Functioni

Catalyzes the dephosphorylation of O-phospho-L-serine into L-serine, a step in the L-serine biosynthetic pathway (PubMed:25037224, PubMed:25521849). Exhibits high specificity for L-phosphoserine compared to substrates like L-phosphothreonine (5% relative activity) and L-phosphotyrosine (1.7% relative activity) (PubMed:25521849).2 Publications
In the host, induces significant cytoskeleton rearrangements through cofilin dephosphorylation and its subsequent activation, and affects the expression of genes that regulate actin dynamics. It specifically interacts with HSP90, HSP70 and HSP27 that block apoptotic pathways but not with other HSPs. Also interacts with GAPDH. It actively dephosphorylates MAP kinase p38 and NF-kappa B p65 (specifically at Ser-536) that play crucial roles in inflammatory and immune responses. This in turn leads to down-regulation of Interleukin 8, a chemotactic and inflammatory cytokine. Thus might help the pathogen to evade the host's immune response (PubMed:26984196). Exogenous addition of purified SerB2 protein to human THP-1 cells (that can be differentiated into macrophage-like cells) induces microtubule rearrangements; the phosphatase activity is co-related to the elicited rearrangements, while addition of the ACT-domains alone elicits no rearrangements (PubMed:25521849).2 Publications

<p>This subsection of the <a href="">Function</a> section describes the catalytic activity of an enzyme, i.e. a chemical reaction that the enzyme catalyzes.<p><a href='/help/catalytic_activity' target='_top'>More...</a></p>Catalytic activityi

<p>This subsection of the 'Function' section provides information relevant to cofactors. A cofactor is any non-protein substance required for a protein to be catalytically active. Some cofactors are inorganic, such as the metal atoms zinc, iron, and copper in various oxidation states. Others, such as most vitamins, are organic.<p><a href='/help/cofactor' target='_top'>More...</a></p>Cofactori

Mg2+2 Publications, Mn2+2 PublicationsNote: Binds 1 Mg2+ ion per subunit (By similarity). Can also use Mn2+ (PubMed:25037224, PubMed:25521849).By similarity2 Publications

<p>This subsection of the <a href="">Function</a> section describes regulatory mechanisms for enzymes, transporters or microbial transcription factors, and reports the components which regulate (by activation or inhibition) the reaction.<p><a href='/help/activity_regulation' target='_top'>More...</a></p>Activity regulationi

Clofazimine, a drug being evaluated for XDR and MDR tuberculosis, inhibits SerB2 phosphatase activity and reverses the various functional effects described above and interactions with host proteins (PubMed:26984196). Is inhibited by known PSP inhibitors such as chlorpromazine, DL-AP3 and sodium orthovanadate, but not by okadaic acid (PubMed:25037224, PubMed:25521849). By binding to the ACT domains, amino-acids have various effects on enzyme activity: L-serine and L-glycine act as inhibitors, whereas L-lysine, L-tyrosine and L-phenylalanine are activators (PubMed:25521849). High throughput screen has been performed to identify specific PSP inhibitors with activity against intracellular bacteria; the two best hits identified in this screen, clorobiocin and rosaniline, are bactericidal and kill bacteria in infected macrophages in a dose-dependent manner (PubMed:25037224).3 Publications

<p>This subsection of the 'Function' section describes biophysical and chemical properties, such as maximal absorption, kinetic parameters, pH dependence, redox potentials and temperature dependence.<p><a href='/help/biophysicochemical_properties' target='_top'>More...</a></p>Kineticsi

kcat is 8.83 min(-1) (PubMed:25037224). kcat is 25400 sec(-1) (PubMed:25521849).2 Publications
  1. KM=92.68 µM for O-phospho-L-serine1 Publication
  2. KM=135.9 µM for O-phospho-L-serine1 Publication
  1. Vmax=14250 nmol/min/mg enzyme1 Publication

pH dependencei

Optimum pH is 7.5 (PubMed:25037224, PubMed:25521849). Activity declines progressively before pH 7.5 and is almost abolished at 6.0 while at higher pH the enzyme remains active till pH 9.0 (PubMed:25521849).2 Publications

Temperature dependencei

Optimum temperature is 37 degrees Celsius. Activity declines at higher temperatures and is completely abolished by 50 degrees Celsius.1 Publication

<p>This subsection of the <a href="">'Function'</a> section describes the metabolic pathway(s) associated with a protein.<p><a href='/help/pathway' target='_top'>More...</a></p>Pathwayi: L-serine biosynthesis

This protein is involved in step 3 of the subpathway that synthesizes L-serine from 3-phospho-D-glycerate.1 Publication
Proteins known to be involved in the 3 steps of the subpathway in this organism are:
  1. D-3-phosphoglycerate dehydrogenase (serA)
  2. Phosphoserine aminotransferase (serC)
  3. Phosphoserine phosphatase SerB2 (serB2)
This subpathway is part of the pathway L-serine biosynthesis, which is itself part of Amino-acid biosynthesis.
View all proteins of this organism that are known to be involved in the subpathway that synthesizes L-serine from 3-phospho-D-glycerate, the pathway L-serine biosynthesis and in Amino-acid biosynthesis.


Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the <a href="">Function</a> section is used for enzymes and indicates the residues directly involved in catalysis.<p><a href='/help/act_site' target='_top'>More...</a></p>Active sitei185NucleophileBy similarity1
<p>This subsection of the <a href="">Function</a> section indicates at which position the protein binds a given metal ion. The nature of the metal is indicated in the 'Description' field.<p><a href='/help/metal' target='_top'>More...</a></p>Metal bindingi185MagnesiumBy similarity1
Active sitei187Proton donorBy similarity1
Metal bindingi187Magnesium; via carbonyl oxygenBy similarity1
<p>This subsection of the <a href="">Function</a> section describes the interaction between a single amino acid and another chemical entity. Priority is given to the annotation of physiological ligands.<p><a href='/help/binding' target='_top'>More...</a></p>Binding sitei194SubstrateBy similarity1
Binding sitei230SubstrateBy similarity1
Binding sitei318SubstrateBy similarity1
Metal bindingi341MagnesiumBy similarity1
Binding sitei344SubstrateBy similarity1

<p>The <a href="">Gene Ontology (GO)</a> project provides a set of hierarchical controlled vocabulary split into 3 categories:<p><a href='/help/gene_ontology' target='_top'>More...</a></p>GO - Molecular functioni

GO - Biological processi

<p>UniProtKB Keywords constitute a <a href="">controlled vocabulary</a> with a hierarchical structure. Keywords summarise the content of a UniProtKB entry and facilitate the search for proteins of interest.<p><a href='/help/keywords' target='_top'>More...</a></p>Keywordsi

Molecular functionHydrolase
Biological processAmino-acid biosynthesis, Serine biosynthesis
LigandMagnesium, Metal-binding

Enzyme and pathway databases

UniPathway: a resource for the exploration and annotation of metabolic pathways


<p>This section provides information about the protein and gene name(s) and synonym(s) and about the organism that is the source of the protein sequence.<p><a href='/help/names_and_taxonomy_section' target='_top'>More...</a></p>Names & Taxonomyi

<p>This subsection of the <a href="">Names and taxonomy</a> section provides an exhaustive list of all names of the protein, from commonly used to obsolete, to allow unambiguous identification of a protein.<p><a href='/help/protein_names' target='_top'>More...</a></p>Protein namesi
Recommended name:
Phosphoserine phosphatase SerB22 Publications (EC: Publications)
Short name:
PSP2 Publications
Short name:
Alternative name(s):
O-phosphoserine phosphohydrolase1 Publication
Protein-serine/threonine phosphatase1 Publication (EC: Publication)
<p>This subsection of the <a href="">Names and taxonomy</a> section indicates the name(s) of the gene(s) that code for the protein sequence(s) described in the entry. Four distinct tokens exist: 'Name', 'Synonyms', 'Ordered locus names' and 'ORF names'.<p><a href='/help/gene_name' target='_top'>More...</a></p>Gene namesi
Name:serB22 PublicationsImported
Ordered Locus Names:Rv3042cImported
<p>This subsection of the <a href="">Names and taxonomy</a> section provides information on the name(s) of the organism that is the source of the protein sequence.<p><a href='/help/organism-name' target='_top'>More...</a></p>OrganismiMycobacterium tuberculosis (strain ATCC 25618 / H37Rv)
<p>This subsection of the <a href="">Names and taxonomy</a> section shows the unique identifier assigned by the NCBI to the source organism of the protein. This is known as the 'taxonomic identifier' or 'taxid'.<p><a href='/help/taxonomic_identifier' target='_top'>More...</a></p>Taxonomic identifieri83332 [NCBI]
<p>This subsection of the <a href="">Names and taxonomy</a> section contains the taxonomic hierarchical classification lineage of the source organism. It lists the nodes as they appear top-down in the taxonomic tree, with the more general grouping listed first.<p><a href='/help/taxonomic_lineage' target='_top'>More...</a></p>Taxonomic lineageiBacteriaActinobacteriaCorynebacterialesMycobacteriaceaeMycobacteriumMycobacterium tuberculosis complex
<p>This subsection of the <a href="">Names and taxonomy</a> section is present for entries that are part of a <a href="">proteome</a>, i.e. of a set of proteins thought to be expressed by organisms whose genomes have been completely sequenced.<p><a href='/help/proteomes_manual' target='_top'>More...</a></p>Proteomesi
  • UP000001584 <p>A UniProt <a href="">proteome</a> can consist of several components.<br></br>The component name refers to the genomic component encoding a set of proteins.<p><a href='/help/proteome_component' target='_top'>More...</a></p> Componenti: Chromosome

Organism-specific databases

Mycobacterium tuberculosis strain H37Rv genome database


<p>This section provides information on the location and the topology of the mature protein in the cell.<p><a href='/help/subcellular_location_section' target='_top'>More...</a></p>Subcellular locationi

Keywords - Cellular componenti

Host cytoplasm, Secreted

<p>This section provides information on the disease(s) and phenotype(s) associated with a protein.<p><a href='/help/pathology_and_biotech_section' target='_top'>More...</a></p>Pathology & Biotechi

<p>This subsection of the 'Pathology and Biotech' section describes the in vivo effects caused by ablation of the gene (or one or more transcripts) coding for the protein described in the entry. This includes gene knockout and knockdown, provided experiments have been performed in the context of a whole organism or a specific tissue, and not at the single-cell level.<p><a href='/help/disruption_phenotype' target='_top'>More...</a></p>Disruption phenotypei

Transposon mutagenesis experiments have identified that SerB2 is essential for the pathogen's viability while SerB1 is not.1 Publication


Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the <a href="">'Pathology and Biotech'</a> section describes the effect of the experimental mutation of one or more amino acid(s) on the biological properties of the protein.<p><a href='/help/mutagen' target='_top'>More...</a></p>Mutagenesisi18G → A: Does not bind L-serine and correspondingly no oligomeric transitions is observed in the presence of L-serine. 1 Publication1
Mutagenesisi108G → A: Does not bind L-serine and correspondingly no oligomeric transitions is observed in the presence of L-serine. 1 Publication1
Mutagenesisi185D → G: Completely abolishes enzymatic activity. 1 Publication1
Mutagenesisi185D → N: Completely abolishes enzymatic activity. 1 Publication1
Mutagenesisi186V → Q: Decreases enzymatic activity by 50%. 1 Publication1
Mutagenesisi187D → N: Decreases enzymatic activity by 15%. 1 Publication1
Mutagenesisi188S → A: No effect on enzymatic activity. 1 Publication1
Mutagenesisi273S → A: Completely abolishes enzymatic activity (PubMed:25521849). Decreases enzymatic activity by 60% (PubMed:25037224). 2 Publications1
Mutagenesisi318K → A: Decreases enzymatic activity by 50%. 1 Publication1
Mutagenesisi318K → E: Completely abolishes enzymatic activity. 1 Publication1
Mutagenesisi341D → G: Decreases enzymatic activity by 80%. 1 Publication1
Mutagenesisi341D → N: Decreases enzymatic activity by 85%. Completely abolishes enzymatic activity, does not elicit cytoskeletal rearrangements, and does not suppress IL-8 production after TNF-alpha stimulation; when associated with N-345. 1 Publication1
Mutagenesisi345D → N: Decreases enzymatic activity by 55%. Completely abolishes enzymatic activity, does not elicit cytoskeletal rearrangements, and does not suppress IL-8 production after TNF-alpha stimulation; when associated with N-341. 1 Publication1

<p>This section describes post-translational modifications (PTMs) and/or processing events.<p><a href='/help/ptm_processing_section' target='_top'>More...</a></p>PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the 'PTM / Processing' section describes the extent of a polypeptide chain in the mature protein following processing or proteolytic cleavage.<p><a href='/help/chain' target='_top'>More...</a></p>ChainiPRO_00004376721 – 409Phosphoserine phosphatase SerB2Add BLAST409

Proteomic databases

PaxDb, a database of protein abundance averages across all three domains of life


<p>This section provides information on the quaternary structure of a protein and on interaction(s) with other proteins or protein complexes.<p><a href='/help/interaction_section' target='_top'>More...</a></p>Interactioni

<p>This subsection of the <a href="">'Interaction'</a> section provides information about the protein quaternary structure and interaction(s) with other proteins or protein complexes (with the exception of physiological receptor-ligand interactions which are annotated in the <a href="">'Function'</a> section).<p><a href='/help/subunit_structure' target='_top'>More...</a></p>Subunit structurei

Homodimer. The dimeric population shifts to a tetramer in the presence of L-serine, which inactivates the enzyme.

1 Publication

Protein-protein interaction databases

STRING: functional protein association networks


<p>This section provides information on the tertiary and secondary structure of a protein.<p><a href='/help/structure_section' target='_top'>More...</a></p>Structurei

3D structure databases

SWISS-MODEL Repository - a database of annotated 3D protein structure models


Database of comparative protein structure models


<p>This section provides information on sequence similarities with other proteins and the domain(s) present in a protein.<p><a href='/help/family_and_domains_section' target='_top'>More...</a></p>Family & Domainsi

Domains and Repeats

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the <a href="">Family and Domains</a> section describes the position and type of a domain, which is defined as a specific combination of secondary structures organized into a characteristic three-dimensional structure or fold.<p><a href='/help/domain' target='_top'>More...</a></p>Domaini8 – 86ACT 1PROSITE-ProRule annotationAdd BLAST79
Domaini102 – 174ACT 21 PublicationAdd BLAST73


Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the 'Family and Domains' section describes a region of interest that cannot be described in other subsections.<p><a href='/help/region' target='_top'>More...</a></p>Regioni273 – 274Substrate bindingBy similarity2

<p>This subsection of the 'Family and domains' section provides general information on the biological role of a domain. The term 'domain' is intended here in its wide acceptation, it may be a structural domain, a transmembrane region or a functional domain. Several domains are described in this subsection.<p><a href='/help/domain_cc' target='_top'>More...</a></p>Domaini

Folds into three domains, i.e. two ACT domains occurring in tandem at the N-terminus followed by the classical phosphatase (PSP) domain. The PSP domain alone is capable of hydrolyzing L-phosphoserine, albeit with much reduced efficacy. The ACT domains are involved in amino acid binding and play an important role in modulating enzymatic activity.1 Publication

<p>This subsection of the 'Family and domains' section provides information about the sequence similarity with other proteins.<p><a href='/help/sequence_similarities' target='_top'>More...</a></p>Sequence similaritiesi

Phylogenomic databases

evolutionary genealogy of genes: Non-supervised Orthologous Groups

COG0560, Bacteria
COG3830, Bacteria

InParanoid: Eukaryotic Ortholog Groups


Identification of Orthologs from Complete Genome Data


Database for complete collections of gene phylogenies


Family and domain databases

Gene3D Structural and Functional Annotation of Protein Families

Gene3Di, 1 hit, 1 hit

Integrated resource of protein families, domains and functional sites

View protein in InterPro
IPR002912, ACT_dom
IPR036412, HAD-like_sf
IPR023214, HAD_sf
IPR023190, Pser_Pase_dom_2
IPR004469, PSP

Structure-Function Linkage Database

SFLDF00029, phosphoserine_phosphatase, 1 hit

Superfamily database of structural and functional annotation

SSF56784, SSF56784, 1 hit

TIGRFAMs; a protein family database

TIGR00338, serB, 1 hit

PROSITE; a protein domain and family database

View protein in PROSITE
PS51671, ACT, 1 hit

<p>This section displays by default the canonical protein sequence and upon request all isoforms described in the entry. It also includes information pertinent to the sequence(s), including <a href="">length</a> and <a href="">molecular weight</a>. The information is filed in different subsections. The current subsections and their content are listed below:<p><a href='/help/sequences_section' target='_top'>More...</a></p>Sequencei

<p>This subsection of the <a href="">Sequence</a> section indicates if the <a href="">canonical sequence</a> displayed by default in the entry is complete or not.<p><a href='/help/sequence_status' target='_top'>More...</a></p>Sequence statusi: Complete.

O53289-1 [UniParc]FASTAAdd to basket
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Mass (Da):43,059
Last modified:June 1, 1998 - v1
<p>The checksum is a form of redundancy check that is calculated from the sequence. It is useful for tracking sequence updates.</p> <p>It should be noted that while, in theory, two different sequences could have the same checksum value, the likelihood that this would happen is extremely low.</p> <p>However UniProtKB may contain entries with identical sequences in case of multiple genes (paralogs).</p> <p>The checksum is computed as the sequence 64-bit Cyclic Redundancy Check value (CRC64) using the generator polynomial: x<sup>64</sup> + x<sup>4</sup> + x<sup>3</sup> + x + 1. The algorithm is described in the ISO 3309 standard. </p> <p class="publication">Press W.H., Flannery B.P., Teukolsky S.A. and Vetterling W.T.<br /> <strong>Cyclic redundancy and other checksums</strong><br /> <a href="">Numerical recipes in C 2nd ed., pp896-902, Cambridge University Press (1993)</a>)</p> Checksum:iA2D5C6A741A2EF89

Sequence databases

Select the link destinations:

EMBL nucleotide sequence database


GenBank nucleotide sequence database


DNA Data Bank of Japan; a nucleotide sequence database

Links Updated
AL123456 Genomic DNA Translation: CCP45851.1

NCBI Reference Sequences

NP_217558.1, NC_000962.3
WP_003912067.1, NZ_NVQJ01000011.1

Genome annotation databases

Database of genes from NCBI RefSeq genomes


KEGG: Kyoto Encyclopedia of Genes and Genomes


Pathosystems Resource Integration Center (PATRIC)


<p>This section provides links to proteins that are similar to the protein sequence(s) described in this entry at different levels of sequence identity thresholds (100%, 90% and 50%) based on their membership in UniProt Reference Clusters (<a href="">UniRef</a>).<p><a href='/help/similar_proteins_section' target='_top'>More...</a></p>Similar proteinsi

<p>This section is used to point to information related to entries and found in data collections other than UniProtKB.<p><a href='/help/cross_references_section' target='_top'>More...</a></p>Cross-referencesi

Sequence databases

Select the link destinations:
Links Updated
AL123456 Genomic DNA Translation: CCP45851.1
RefSeqiNP_217558.1, NC_000962.3
WP_003912067.1, NZ_NVQJ01000011.1

3D structure databases


Protein-protein interaction databases


Proteomic databases


Genome annotation databases


Organism-specific databases


Phylogenomic databases

eggNOGiCOG0560, Bacteria
COG3830, Bacteria

Enzyme and pathway databases


Family and domain databases

Gene3Di1.10.150.210, 1 hit, 1 hit
InterProiView protein in InterPro
IPR002912, ACT_dom
IPR036412, HAD-like_sf
IPR023214, HAD_sf
IPR023190, Pser_Pase_dom_2
IPR004469, PSP
SFLDiSFLDF00029, phosphoserine_phosphatase, 1 hit
SUPFAMiSSF56784, SSF56784, 1 hit
TIGRFAMsiTIGR00338, serB, 1 hit
PROSITEiView protein in PROSITE
PS51671, ACT, 1 hit

ProtoNet; Automatic hierarchical classification of proteins


MobiDB: a database of protein disorder and mobility annotations


<p>This section provides general information on the entry.<p><a href='/help/entry_information_section' target='_top'>More...</a></p>Entry informationi

<p>This subsection of the 'Entry information' section provides a mnemonic identifier for a UniProtKB entry, but it is not a stable identifier. Each reviewed entry is assigned a unique entry name upon integration into UniProtKB/Swiss-Prot.<p><a href='/help/entry_name' target='_top'>More...</a></p>Entry nameiSERB2_MYCTU
<p>This subsection of the 'Entry information' section provides one or more accession number(s). These are stable identifiers and should be used to cite UniProtKB entries. Upon integration into UniProtKB, each entry is assigned a unique accession number, which is called 'Primary (citable) accession number'.<p><a href='/help/accession_numbers' target='_top'>More...</a></p>AccessioniPrimary (citable) accession number: O53289
Secondary accession number(s): I6X638
<p>This subsection of the 'Entry information' section shows the date of integration of the entry into UniProtKB, the date of the last sequence update and the date of the last annotation modification ('Last modified'). The version number for both the entry and the <a href="">canonical sequence</a> are also displayed.<p><a href='/help/entry_history' target='_top'>More...</a></p>Entry historyiIntegrated into UniProtKB/Swiss-Prot: November 2, 2016
Last sequence update: June 1, 1998
Last modified: April 7, 2021
This is version 132 of the entry and version 1 of the sequence. See complete history.
<p>This subsection of the 'Entry information' section indicates whether the entry has been manually annotated and reviewed by UniProtKB curators or not, in other words, if the entry belongs to the Swiss-Prot section of UniProtKB (<strong>reviewed</strong>) or to the computer-annotated TrEMBL section (<strong>unreviewed</strong>).<p><a href='/help/entry_status' target='_top'>More...</a></p>Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programProkaryotic Protein Annotation Program

<p>This section contains any relevant information that doesn't fit in any other defined sections<p><a href='/help/miscellaneous_section' target='_top'>More...</a></p>Miscellaneousi

Keywords - Technical termi

Reference proteome


  1. PATHWAY comments
    Index of metabolic and biosynthesis pathways
  2. SIMILARITY comments
    Index of protein domains and families
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