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Entry version 137 (07 Apr 2021)
Sequence version 2 (01 Nov 1995)
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Protein

Complement C1q subcomponent subunit B

Gene

C1qb

Organism
Rattus norvegicus (Rat)
Status
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

C1q associates with the proenzymes C1r and C1s to yield C1, the first component of the serum complement system. The collagen-like regions of C1q interact with the Ca2+-dependent C1r2C1s2 proenzyme complex, and efficient activation of C1 takes place on interaction of the globular heads of C1q with the Fc regions of IgG or IgM antibody present in immune complexes.

<p>The <a href="http://www.geneontology.org/">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="http://www.uniprot.org/keywords">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

Biological processComplement pathway, Immunity, Innate immunity

Enzyme and pathway databases

Reactome - a knowledgebase of biological pathways and processes

More...
Reactomei
R-RNO-166663, Initial triggering of complement
R-RNO-173623, Classical antibody-mediated complement activation
R-RNO-977606, Regulation of Complement cascade

<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="http://www.uniprot.org/help/names%5Fand%5Ftaxonomy%5Fsection">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:
Complement C1q subcomponent subunit B
<p>This subsection of the <a href="http://www.uniprot.org/help/names%5Fand%5Ftaxonomy%5Fsection">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:C1qb
<p>This subsection of the <a href="http://www.uniprot.org/help/names%5Fand%5Ftaxonomy%5Fsection">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>OrganismiRattus norvegicus (Rat)
<p>This subsection of the <a href="http://www.uniprot.org/help/names%5Fand%5Ftaxonomy%5Fsection">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 identifieri10116 [NCBI]
<p>This subsection of the <a href="http://www.uniprot.org/help/names%5Fand%5Ftaxonomy%5Fsection">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 lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresGliresRodentiaMyomorphaMuroideaMuridaeMurinaeRattus
<p>This subsection of the <a href="http://www.uniprot.org/help/names%5Fand%5Ftaxonomy%5Fsection">Names and taxonomy</a> section is present for entries that are part of a <a href="http://www.uniprot.org/proteomes">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
  • UP000002494 <p>A UniProt <a href="http://www.uniprot.org/manual/proteomes%5Fmanual">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: Unplaced

Organism-specific databases

Rat genome database

More...
RGDi
2229, C1qb

<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

Secreted

<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 denotes the presence of an N-terminal signal peptide.<p><a href='/help/signal' target='_top'>More...</a></p>Signal peptidei1 – 25By similarityAdd BLAST25
<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_000000352326 – 253Complement C1q subcomponent subunit BAdd BLAST228

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the 'PTM / Processing' section specifies the position and type of each modified residue excluding <a href="http://www.uniprot.org/manual/lipid">lipids</a>, <a href="http://www.uniprot.org/manual/carbohyd">glycans</a> and <a href="http://www.uniprot.org/manual/crosslnk">protein cross-links</a>.<p><a href='/help/mod_res' target='_top'>More...</a></p>Modified residuei26Pyrrolidone carboxylic acidBy similarity1
<p>This subsection of the PTM / Processing":/help/ptm_processing_section section describes the positions of cysteine residues participating in disulfide bonds.<p><a href='/help/disulfid' target='_top'>More...</a></p>Disulfide bondi29Interchain (with C-26 in chain A)
Modified residuei334-hydroxyprolineBy similarity1
Modified residuei364-hydroxyprolineBy similarity1
Modified residuei394-hydroxyprolineBy similarity1
Modified residuei514-hydroxyprolineBy similarity1
Modified residuei544-hydroxyprolineBy similarity1
Modified residuei575-hydroxylysineBy similarity1
Modified residuei605-hydroxylysineBy similarity1
Modified residuei634-hydroxyprolineBy similarity1
Modified residuei755-hydroxylysineBy similarity1
Modified residuei814-hydroxyprolineBy similarity1
Modified residuei844-hydroxyprolineBy similarity1
Modified residuei905-hydroxylysineBy similarity1
Modified residuei965-hydroxylysineBy similarity1
Modified residuei994-hydroxyprolineBy similarity1
Modified residuei1024-hydroxyprolineBy similarity1
Modified residuei1085-hydroxylysineBy similarity1

<p>This subsection of the <a href="http://www.uniprot.org/help/ptm%5Fprocessing%5Fsection">PTM/processing</a> section describes post-translational modifications (PTMs). This subsection <strong>complements</strong> the information provided at the sequence level or describes modifications for which <strong>position-specific data is not yet available</strong>.<p><a href='/help/post-translational_modification' target='_top'>More...</a></p>Post-translational modificationi

Hydroxylated on lysine and proline residues. Hydroxylated lysine residues can be glycosylated.

Keywords - PTMi

Disulfide bond, Glycoprotein, Hydroxylation, Pyrrolidone carboxylic acid

Proteomic databases

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

More...
PaxDbi
P31721

PRoteomics IDEntifications database

More...
PRIDEi
P31721

PTM databases

iPTMnet integrated resource for PTMs in systems biology context

More...
iPTMneti
P31721

Comprehensive resource for the study of protein post-translational modifications (PTMs) in human, mouse and rat.

More...
PhosphoSitePlusi
P31721

<p>This section provides information on the expression of a gene at the mRNA or protein level in cells or in tissues of multicellular organisms.<p><a href='/help/expression_section' target='_top'>More...</a></p>Expressioni

<p>This subsection of the 'Expression' section provides information on the expression of a gene at the mRNA or protein level in cells or in tissues of multicellular organisms. By default, the information is derived from experiments at the mRNA level, unless specified 'at protein level'.<br></br>Examples: <a href="http://www.uniprot.org/uniprot/P92958#expression">P92958</a>, <a href="http://www.uniprot.org/uniprot/Q8TDN4#expression">Q8TDN4</a>, <a href="http://www.uniprot.org/uniprot/O14734#expression">O14734</a><p><a href='/help/tissue_specificity' target='_top'>More...</a></p>Tissue specificityi

Highest levels in spleen, lung and brain. Weaker expression in kidney and liver. In the spleen, localized mainly to the red pulp, in cells mainly of monocyte-macrophage lineage. In white pulp, localized in specific dendritic cells such as those from the periarteriolar lymphatic sheath (PALS).1 Publication

<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="http://www.uniprot.org/help/interaction%5Fsection">'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="http://www.uniprot.org/help/function%5Fsection">'Function'</a> section).<p><a href='/help/subunit_structure' target='_top'>More...</a></p>Subunit structurei

C1 is a calcium-dependent trimolecular complex of C1q, C1r and C1s in the molar ration of 1:2:2. C1q subcomponent is composed of nine subunits, six of which are disulfide-linked dimers of the a and B chains, and three of which are disulfide-linked dimers of the C chain. In addition to the major A:B and C:C dimer bands, rat, unlike human C1q, contained minor dimer species.

GO - Molecular functioni

Protein-protein interaction databases

The Biological General Repository for Interaction Datasets (BioGRID)

More...
BioGRIDi
248307, 2 interactors

Protein interaction database and analysis system

More...
IntActi
P31721, 1 interactor

STRING: functional protein association networks

More...
STRINGi
10116.ENSRNOP00000017060

<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

More...
SMRi
P31721

Database of comparative protein structure models

More...
ModBasei
Search...

<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="http://www.uniprot.org/help/family%5Fand%5Fdomains%5Fsection">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>Domaini29 – 112Collagen-likeAdd BLAST84
Domaini115 – 253C1qPROSITE-ProRule annotationAdd BLAST139

Keywords - Domaini

Collagen, Repeat, Signal

Phylogenomic databases

evolutionary genealogy of genes: Non-supervised Orthologous Groups

More...
eggNOGi
ENOG502RYR2, Eukaryota

InParanoid: Eukaryotic Ortholog Groups

More...
InParanoidi
P31721

Database of Orthologous Groups

More...
OrthoDBi
1258047at2759

Database for complete collections of gene phylogenies

More...
PhylomeDBi
P31721

Family and domain databases

Gene3D Structural and Functional Annotation of Protein Families

More...
Gene3Di
2.60.120.40, 1 hit

Integrated resource of protein families, domains and functional sites

More...
InterProi
View protein in InterPro
IPR001073, C1q_dom
IPR008160, Collagen
IPR037573, Complement_C1qB
IPR008983, Tumour_necrosis_fac-like_dom

The PANTHER Classification System

More...
PANTHERi
PTHR15427:SF18, PTHR15427:SF18, 1 hit

Pfam protein domain database

More...
Pfami
View protein in Pfam
PF00386, C1q, 1 hit
PF01391, Collagen, 2 hits

Protein Motif fingerprint database; a protein domain database

More...
PRINTSi
PR00007, COMPLEMNTC1Q

Simple Modular Architecture Research Tool; a protein domain database

More...
SMARTi
View protein in SMART
SM00110, C1Q, 1 hit

Superfamily database of structural and functional annotation

More...
SUPFAMi
SSF49842, SSF49842, 1 hit

PROSITE; a protein domain and family database

More...
PROSITEi
View protein in PROSITE
PS50871, C1Q, 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="http://www.uniprot.org/help/sequence%5Flength">length</a> and <a href="http://www.uniprot.org/help/sequences">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>Sequence (1+)i

<p>This subsection of the <a href="http://www.uniprot.org/help/sequences%5Fsection">Sequence</a> section indicates if the <a href="http://www.uniprot.org/help/canonical%5Fand%5Fisoforms">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.

<p>This subsection of the <a href="http://www.uniprot.org/help/sequences%5Fsection">Sequence</a> section indicates if the <a href="http://www.uniprot.org/help/canonical%5Fand%5Fisoforms">canonical sequence</a> displayed by default in the entry is in its mature form or if it represents the precursor.<p><a href='/help/sequence_processing' target='_top'>More...</a></p>Sequence processingi: The displayed sequence is further processed into a mature form.

This entry has 1 described isoform and 1 potential isoform that is computationally mapped.Show allAlign All

P31721-1 [UniParc]FASTAAdd to basket
« Hide
        10         20         30         40         50
MKTQWSEILT PLLLLLLGLL HVSWAQSSCT GSPGIPGVPG IPGVPGSDGK
60 70 80 90 100
PGTPGIKGEK GLPGLAGDHG ELGEKGDAGI PGIPGKVGPK GPVGPKGAPG
110 120 130 140 150
PPGPRGPKGG SGDYKATQKV AFSALRTVNS ALRPNQAIRF EKVITNVNDN
160 170 180 190 200
YEPRSGKFTC KVPGLYYFTY HASSRGNLCV NIVRGRDRDR MQKVLTFCDY
210 220 230 240 250
AQNTFQVTTG GVVLKLEQEE VVHLQATDKN SLLGVEGANS IFTGFLLFPD

MDV
Length:253
Mass (Da):26,589
Last modified:November 1, 1995 - v2
<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="http://www.nrbook.com/b/bookcpdf.php">Numerical recipes in C 2nd ed., pp896-902, Cambridge University Press (1993)</a>)</p> Checksum:i1CB40622571BFC9B
GO

<p>In eukaryotic reference proteomes, unreviewed entries that are likely to belong to the same gene are computationally mapped, based on gene identifiers from Ensembl, EnsemblGenomes and model organism databases.<p><a href='/help/gene_centric_isoform_mapping' target='_top'>More...</a></p>Computationally mapped potential isoform sequencesi

There is 1 potential isoform mapped to this entry.BLASTAlignShow allAdd to basket
EntryEntry nameProtein names
Gene namesLengthAnnotation
G3V7N9G3V7N9_RAT
Adiponectin a
C1qb Adia, rCG_30695
253Annotation score:

Annotation score:2 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>

Sequence databases

Select the link destinations:

EMBL nucleotide sequence database

More...
EMBLi

GenBank nucleotide sequence database

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GenBanki

DNA Data Bank of Japan; a nucleotide sequence database

More...
DDBJi
Links Updated
X71127 mRNA Translation: CAA50440.1

Protein sequence database of the Protein Information Resource

More...
PIRi
S49158

NCBI Reference Sequences

More...
RefSeqi
NP_062135.1, NM_019262.1

Genome annotation databases

Database of genes from NCBI RefSeq genomes

More...
GeneIDi
29687

KEGG: Kyoto Encyclopedia of Genes and Genomes

More...
KEGGi
rno:29687

<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="http://www.uniprot.org/help/uniref">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:
EMBLi
GenBanki
DDBJi
Links Updated
X71127 mRNA Translation: CAA50440.1
PIRiS49158
RefSeqiNP_062135.1, NM_019262.1

3D structure databases

SMRiP31721
ModBaseiSearch...

Protein-protein interaction databases

BioGRIDi248307, 2 interactors
IntActiP31721, 1 interactor
STRINGi10116.ENSRNOP00000017060

PTM databases

iPTMnetiP31721
PhosphoSitePlusiP31721

Proteomic databases

PaxDbiP31721
PRIDEiP31721

Genome annotation databases

GeneIDi29687
KEGGirno:29687

Organism-specific databases

Comparative Toxicogenomics Database

More...
CTDi
713
RGDi2229, C1qb

Phylogenomic databases

eggNOGiENOG502RYR2, Eukaryota
InParanoidiP31721
OrthoDBi1258047at2759
PhylomeDBiP31721

Enzyme and pathway databases

ReactomeiR-RNO-166663, Initial triggering of complement
R-RNO-173623, Classical antibody-mediated complement activation
R-RNO-977606, Regulation of Complement cascade

Miscellaneous databases

Protein Ontology

More...
PROi
PR:P31721

Family and domain databases

Gene3Di2.60.120.40, 1 hit
InterProiView protein in InterPro
IPR001073, C1q_dom
IPR008160, Collagen
IPR037573, Complement_C1qB
IPR008983, Tumour_necrosis_fac-like_dom
PANTHERiPTHR15427:SF18, PTHR15427:SF18, 1 hit
PfamiView protein in Pfam
PF00386, C1q, 1 hit
PF01391, Collagen, 2 hits
PRINTSiPR00007, COMPLEMNTC1Q
SMARTiView protein in SMART
SM00110, C1Q, 1 hit
SUPFAMiSSF49842, SSF49842, 1 hit
PROSITEiView protein in PROSITE
PS50871, C1Q, 1 hit

ProtoNet; Automatic hierarchical classification of proteins

More...
ProtoNeti
Search...

MobiDB: a database of protein disorder and mobility annotations

More...
MobiDBi
Search...

<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 nameiC1QB_RAT
<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: P31721
<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="http://www.uniprot.org/help/canonical%5Fand%5Fisoforms">canonical sequence</a> are also displayed.<p><a href='/help/entry_history' target='_top'>More...</a></p>Entry historyiIntegrated into UniProtKB/Swiss-Prot: July 1, 1993
Last sequence update: November 1, 1995
Last modified: April 7, 2021
This is version 137 of the entry and version 2 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 programChordata 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

Direct protein sequencing, Reference proteome
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