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Protein

Pulmonary surfactant-associated protein B

Gene

SFTPB

Organism
Homo sapiens (Human)
Status
Reviewed-Annotation score: Annotation score: 5 out of 5-Experimental evidence at protein leveli

Functioni

Pulmonary surfactant-associated proteins promote alveolar stability by lowering the surface tension at the air-liquid interface in the peripheral air spaces. SP-B increases the collapse pressure of palmitic acid to nearly 70 millinewtons per meter.

GO - Molecular functioni

GO - Biological processi

  • animal organ morphogenesis Source: ProtInc
  • cellular protein metabolic process Source: Reactome
  • respiratory gaseous exchange Source: ProtInc
  • sphingolipid metabolic process Source: InterPro
Complete GO annotation...

Keywords - Biological processi

Gaseous exchange

Enzyme and pathway databases

BioCyciZFISH:ENSG00000168878-MONOMER.
ReactomeiR-HSA-5683678. Defective ABCA3 causes pulmonary surfactant metabolism dysfunction type 3 (SMDP3).
R-HSA-5683826. Surfactant metabolism.
R-HSA-5688031. Defective pro-SFTPB causes pulmonary surfactant metabolism dysfunction 1 (SMDP1) and respiratory distress syndrome (RDS).
R-HSA-5688354. Defective pro-SFTPC causes pulmonary surfactant metabolism dysfunction 2 (SMDP2) and respiratory distress syndrome (RDS).
R-HSA-5688849. Defective CSF2RB causes pulmonary surfactant metabolism dysfunction 5 (SMDP5).
R-HSA-5688890. Defective CSF2RA causes pulmonary surfactant metabolism dysfunction 4 (SMDP4).

Names & Taxonomyi

Protein namesi
Recommended name:
Pulmonary surfactant-associated protein B
Short name:
SP-B
Alternative name(s):
18 kDa pulmonary-surfactant protein
6 kDa protein
Pulmonary surfactant-associated proteolipid SPL(Phe)
Gene namesi
Name:SFTPB
Synonyms:SFTP3
OrganismiHomo sapiens (Human)
Taxonomic identifieri9606 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniHominidaeHomo
Proteomesi
  • UP000005640 Componenti: Chromosome 2

Organism-specific databases

HGNCiHGNC:10801. SFTPB.

Subcellular locationi

GO - Cellular componenti

Complete GO annotation...

Keywords - Cellular componenti

Secreted, Surface film

Pathology & Biotechi

Involvement in diseasei

Pulmonary surfactant metabolism dysfunction 1 (SMDP1)1 Publication
The disease is caused by mutations affecting the gene represented in this entry.
Disease descriptionA rare lung disorder due to impaired surfactant homeostasis. It is characterized by alveolar filling with floccular material that stains positive using the periodic acid-Schiff method and is derived from surfactant phospholipids and protein components. Excessive lipoproteins accumulation in the alveoli results in severe respiratory distress.
See also OMIM:265120
Feature keyPosition(s)DescriptionActionsGraphical viewLength
Natural variantiVAR_036856236R → C in SMDP1. 1 PublicationCorresponds to variant rs137853202dbSNPEnsembl.1
Respiratory distress syndrome in premature infants (RDS)1 Publication
Disease susceptibility may be associated with variations affecting the gene represented in this entry. A variation Ile to Thr at position 131 influences the association between specific alleles of SFTPA1 and respiratory distress syndrome in premature infants.
Disease descriptionA lung disease affecting usually premature newborn infants. It is characterized by deficient gas exchange, diffuse atelectasis, high-permeability lung edema and fibrin-rich alveolar deposits called 'hyaline membranes'.
See also OMIM:267450

Keywords - Diseasei

Disease mutation

Organism-specific databases

DisGeNETi6439.
MalaCardsiSFTPB.
MIMi265120. phenotype.
267450. phenotype.
OpenTargetsiENSG00000168878.
Orphaneti264675. Congenital pulmonary alveolar proteinosis.
70587. Infant acute respiratory distress syndrome.
217563. Neonatal acute respiratory distress with surfactant metabolism deficiency.
PharmGKBiPA35713.

Polymorphism and mutation databases

BioMutaiSFTPB.
DMDMi131418.

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Signal peptidei1 – 24Sequence analysisAdd BLAST24
PropeptideiPRO_000003164725 – 200Add BLAST176
ChainiPRO_0000031648201 – 279Pulmonary surfactant-associated protein BAdd BLAST79
PropeptideiPRO_0000031649280 – 381Add BLAST102

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Disulfide bondi69 ↔ 143PROSITE-ProRule annotation
Disulfide bondi72 ↔ 137PROSITE-ProRule annotation
Disulfide bondi100 ↔ 112PROSITE-ProRule annotation
Glycosylationi129N-linked (GlcNAc...)PROSITE-ProRule annotation1
Disulfide bondi208 ↔ 277PROSITE-ProRule annotation1 Publication
Disulfide bondi211 ↔ 271PROSITE-ProRule annotation1 Publication
Disulfide bondi235 ↔ 246PROSITE-ProRule annotation1 Publication
Disulfide bondi248InterchainPROSITE-ProRule annotation1 Publication
Disulfide bondi299 ↔ 366PROSITE-ProRule annotation
Disulfide bondi302 ↔ 360PROSITE-ProRule annotation
Glycosylationi311N-linked (GlcNAc...)PROSITE-ProRule annotation1
Disulfide bondi325 ↔ 335PROSITE-ProRule annotation

Keywords - PTMi

Disulfide bond, Glycoprotein

Proteomic databases

PaxDbiP07988.
PeptideAtlasiP07988.
PRIDEiP07988.

Miscellaneous databases

PMAP-CutDBP07988.

Expressioni

Gene expression databases

BgeeiENSG00000168878.
CleanExiHS_SFTPB.
ExpressionAtlasiP07988. baseline and differential.
GenevisibleiP07988. HS.

Organism-specific databases

HPAiCAB002440.
HPA034820.
HPA062148.

Interactioni

Subunit structurei

Homodimer; disulfide-linked.1 Publication

GO - Molecular functioni

Protein-protein interaction databases

STRINGi9606.ENSP00000377409.

Structurei

Secondary structure

1381
Legend: HelixTurnBeta strandPDB Structure known for this area
Show more details
Feature keyPosition(s)DescriptionActionsGraphical viewLength
Helixi213 – 221Combined sources9
Helixi260 – 263Combined sources4
Beta strandi265 – 268Combined sources4
Helixi269 – 276Combined sources8

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
PDB entryMethodResolution (Å)ChainPositionsPDBsum
1DFWinfrared-A201-225[»]
1KMRNMR-A211-225[»]
1RG3NMR-A263-278[»]
1RG4NMR-A263-278[»]
1SSZinfrared-A208-278[»]
2DWFNMR-A208-278[»]
2JOUNMR-A208-278[»]
2M0HNMR-A259-280[»]
2M1TNMR-A259-278[»]
ProteinModelPortaliP07988.
SMRiP07988.
ModBaseiSearch...
MobiDBiSearch...

Miscellaneous databases

EvolutionaryTraceiP07988.

Family & Domainsi

Domains and Repeats

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Domaini25 – 65Saposin A-typePROSITE-ProRule annotationAdd BLAST41
Domaini65 – 147Saposin B-type 1PROSITE-ProRule annotationAdd BLAST83
Domaini204 – 281Saposin B-type 2PROSITE-ProRule annotationAdd BLAST78
Domaini295 – 370Saposin B-type 3PROSITE-ProRule annotationAdd BLAST76

Sequence similaritiesi

Contains 1 saposin A-type domain.PROSITE-ProRule annotation
Contains 3 saposin B-type domains.PROSITE-ProRule annotation

Keywords - Domaini

Repeat, Signal

Phylogenomic databases

eggNOGiKOG1340. Eukaryota.
ENOG410XSI5. LUCA.
GeneTreeiENSGT00530000063434.
HOGENOMiHOG000115745.
HOVERGENiHBG006905.
InParanoidiP07988.
PhylomeDBiP07988.

Family and domain databases

Gene3Di1.10.225.10. 3 hits.
InterProiIPR003119. SAP_A.
IPR007856. SapB_1.
IPR008138. SapB_2.
IPR008373. Saposin.
IPR011001. Saposin-like.
IPR008139. SaposinB_dom.
[Graphical view]
PfamiPF02199. SapA. 1 hit.
PF05184. SapB_1. 1 hit.
PF03489. SapB_2. 2 hits.
[Graphical view]
PRINTSiPR01797. SAPOSIN.
SMARTiSM00162. SAPA. 1 hit.
SM00741. SapB. 3 hits.
[Graphical view]
SUPFAMiSSF47862. SSF47862. 3 hits.
PROSITEiPS51110. SAP_A. 1 hit.
PS50015. SAP_B. 3 hits.
[Graphical view]

Sequencei

Sequence statusi: Complete.

Sequence processingi: The displayed sequence is further processed into a mature form.

P07988-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MAESHLLQWL LLLLPTLCGP GTAAWTTSSL ACAQGPEFWC QSLEQALQCR
60 70 80 90 100
ALGHCLQEVW GHVGADDLCQ ECEDIVHILN KMAKEAIFQD TMRKFLEQEC
110 120 130 140 150
NVLPLKLLMP QCNQVLDDYF PLVIDYFQNQ TDSNGICMHL GLCKSRQPEP
160 170 180 190 200
EQEPGMSDPL PKPLRDPLPD PLLDKLVLPV LPGALQARPG PHTQDLSEQQ
210 220 230 240 250
FPIPLPYCWL CRALIKRIQA MIPKGALAVA VAQVCRVVPL VAGGICQCLA
260 270 280 290 300
ERYSVILLDT LLGRMLPQLV CRLVLRCSMD DSAGPRSPTG EWLPRDSECH
310 320 330 340 350
LCMSVTTQAG NSSEQAIPQA MLQACVGSWL DREKCKQFVE QHTPQLLTLV
360 370 380
PRGWDAHTTC QALGVCGTMS SPLQCIHSPD L
Length:381
Mass (Da):42,117
Last modified:May 1, 1992 - v3
Checksum:i9FD7F66678A35153
GO

Sequence cautioni

The sequence AAA88099 differs from that shown. Reason: Erroneous initiation.Curated

Experimental Info

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Sequence conflicti178L → V in AAA36628 (PubMed:3343343).Curated1
Sequence conflicti318P → L in AAA88099 (PubMed:3035561).Curated1

Natural variant

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Natural variantiVAR_006948131T → I.2 PublicationsCorresponds to variant rs1130866dbSNPEnsembl.1
Natural variantiVAR_013099176L → F.1 PublicationCorresponds to variant rs3024801dbSNPEnsembl.1
Natural variantiVAR_006950228A → I Requires 2 nucleotide substitutions. 1 Publication1
Natural variantiVAR_006949228A → R Requires 2 nucleotide substitutions. 2 Publications1
Natural variantiVAR_036856236R → C in SMDP1. 1 PublicationCorresponds to variant rs137853202dbSNPEnsembl.1
Natural variantiVAR_013100272R → H.1 PublicationCorresponds to variant rs3024809dbSNPEnsembl.1

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
J02761 mRNA. Translation: AAA60212.1.
M24461 Genomic DNA. Translation: AAB59541.1.
AF400074 Genomic DNA. Translation: AAK77913.1.
BC032785 mRNA. Translation: AAH32785.1.
M16764 mRNA. Translation: AAA88099.1. Different initiation.
M19097 mRNA. Translation: AAA36628.1.
PIRiA31361. LNHUB.
RefSeqiNP_000533.3. NM_000542.3.
NP_942140.2. NM_198843.2.
UniGeneiHs.512690.

Genome annotation databases

EnsembliENST00000393822; ENSP00000377409; ENSG00000168878.
ENST00000519937; ENSP00000428719; ENSG00000168878.
GeneIDi6439.
KEGGihsa:6439.
UCSCiuc061lja.1. human.

Keywords - Coding sequence diversityi

Polymorphism

Cross-referencesi

Web resourcesi

SeattleSNPs

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
J02761 mRNA. Translation: AAA60212.1.
M24461 Genomic DNA. Translation: AAB59541.1.
AF400074 Genomic DNA. Translation: AAK77913.1.
BC032785 mRNA. Translation: AAH32785.1.
M16764 mRNA. Translation: AAA88099.1. Different initiation.
M19097 mRNA. Translation: AAA36628.1.
PIRiA31361. LNHUB.
RefSeqiNP_000533.3. NM_000542.3.
NP_942140.2. NM_198843.2.
UniGeneiHs.512690.

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
PDB entryMethodResolution (Å)ChainPositionsPDBsum
1DFWinfrared-A201-225[»]
1KMRNMR-A211-225[»]
1RG3NMR-A263-278[»]
1RG4NMR-A263-278[»]
1SSZinfrared-A208-278[»]
2DWFNMR-A208-278[»]
2JOUNMR-A208-278[»]
2M0HNMR-A259-280[»]
2M1TNMR-A259-278[»]
ProteinModelPortaliP07988.
SMRiP07988.
ModBaseiSearch...
MobiDBiSearch...

Protein-protein interaction databases

STRINGi9606.ENSP00000377409.

Polymorphism and mutation databases

BioMutaiSFTPB.
DMDMi131418.

Proteomic databases

PaxDbiP07988.
PeptideAtlasiP07988.
PRIDEiP07988.

Protocols and materials databases

DNASUi6439.
Structural Biology KnowledgebaseSearch...

Genome annotation databases

EnsembliENST00000393822; ENSP00000377409; ENSG00000168878.
ENST00000519937; ENSP00000428719; ENSG00000168878.
GeneIDi6439.
KEGGihsa:6439.
UCSCiuc061lja.1. human.

Organism-specific databases

CTDi6439.
DisGeNETi6439.
GeneCardsiSFTPB.
HGNCiHGNC:10801. SFTPB.
HPAiCAB002440.
HPA034820.
HPA062148.
MalaCardsiSFTPB.
MIMi178640. gene.
265120. phenotype.
267450. phenotype.
neXtProtiNX_P07988.
OpenTargetsiENSG00000168878.
Orphaneti264675. Congenital pulmonary alveolar proteinosis.
70587. Infant acute respiratory distress syndrome.
217563. Neonatal acute respiratory distress with surfactant metabolism deficiency.
PharmGKBiPA35713.
GenAtlasiSearch...

Phylogenomic databases

eggNOGiKOG1340. Eukaryota.
ENOG410XSI5. LUCA.
GeneTreeiENSGT00530000063434.
HOGENOMiHOG000115745.
HOVERGENiHBG006905.
InParanoidiP07988.
PhylomeDBiP07988.

Enzyme and pathway databases

BioCyciZFISH:ENSG00000168878-MONOMER.
ReactomeiR-HSA-5683678. Defective ABCA3 causes pulmonary surfactant metabolism dysfunction type 3 (SMDP3).
R-HSA-5683826. Surfactant metabolism.
R-HSA-5688031. Defective pro-SFTPB causes pulmonary surfactant metabolism dysfunction 1 (SMDP1) and respiratory distress syndrome (RDS).
R-HSA-5688354. Defective pro-SFTPC causes pulmonary surfactant metabolism dysfunction 2 (SMDP2) and respiratory distress syndrome (RDS).
R-HSA-5688849. Defective CSF2RB causes pulmonary surfactant metabolism dysfunction 5 (SMDP5).
R-HSA-5688890. Defective CSF2RA causes pulmonary surfactant metabolism dysfunction 4 (SMDP4).

Miscellaneous databases

ChiTaRSiSFTPB. human.
EvolutionaryTraceiP07988.
GeneWikiiPulmonary_surfactant-associated_protein_B.
GenomeRNAii6439.
PMAP-CutDBP07988.
PROiP07988.
SOURCEiSearch...

Gene expression databases

BgeeiENSG00000168878.
CleanExiHS_SFTPB.
ExpressionAtlasiP07988. baseline and differential.
GenevisibleiP07988. HS.

Family and domain databases

Gene3Di1.10.225.10. 3 hits.
InterProiIPR003119. SAP_A.
IPR007856. SapB_1.
IPR008138. SapB_2.
IPR008373. Saposin.
IPR011001. Saposin-like.
IPR008139. SaposinB_dom.
[Graphical view]
PfamiPF02199. SapA. 1 hit.
PF05184. SapB_1. 1 hit.
PF03489. SapB_2. 2 hits.
[Graphical view]
PRINTSiPR01797. SAPOSIN.
SMARTiSM00162. SAPA. 1 hit.
SM00741. SapB. 3 hits.
[Graphical view]
SUPFAMiSSF47862. SSF47862. 3 hits.
PROSITEiPS51110. SAP_A. 1 hit.
PS50015. SAP_B. 3 hits.
[Graphical view]
ProtoNetiSearch...

Entry informationi

Entry nameiPSPB_HUMAN
AccessioniPrimary (citable) accession number: P07988
Secondary accession number(s): Q96R04
Entry historyi
Integrated into UniProtKB/Swiss-Prot: August 1, 1988
Last sequence update: May 1, 1992
Last modified: November 2, 2016
This is version 186 of the entry and version 3 of the sequence. [Complete history]
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programChordata Protein Annotation Program
DisclaimerAny medical or genetic information present in this entry is provided for research, educational and informational purposes only. It is not in any way intended to be used as a substitute for professional medical advice, diagnosis, treatment or care.

Miscellaneousi

Miscellaneous

Pulmonary surfactant consists of 90% lipid and 10% protein. There are 4 surfactant-associated proteins: 2 collagenous, carbohydrate-binding glycoproteins (SP-A and SP-D) and 2 small hydrophobic proteins (SP-B and SP-C).

Keywords - Technical termi

3D-structure, Complete proteome, Direct protein sequencing, Reference proteome

Documents

  1. Human chromosome 2
    Human chromosome 2: entries, gene names and cross-references to MIM
  2. Human entries with polymorphisms or disease mutations
    List of human entries with polymorphisms or disease mutations
  3. Human polymorphisms and disease mutations
    Index of human polymorphisms and disease mutations
  4. MIM cross-references
    Online Mendelian Inheritance in Man (MIM) cross-references in UniProtKB/Swiss-Prot
  5. PDB cross-references
    Index of Protein Data Bank (PDB) cross-references
  6. SIMILARITY comments
    Index of protein domains and families

Similar proteinsi

Links to similar proteins from the UniProt Reference Clusters (UniRef) at 100%, 90% and 50% sequence identity:
100%UniRef100 combines identical sequences and sub-fragments with 11 or more residues from any organism into one UniRef entry.
90%UniRef90 is built by clustering UniRef100 sequences that have at least 90% sequence identity to, and 80% overlap with, the longest sequence (a.k.a seed sequence).
50%UniRef50 is built by clustering UniRef90 seed sequences that have at least 50% sequence identity to, and 80% overlap with, the longest sequence in the cluster.