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P07988 (PSPB_HUMAN) Reviewed, UniProtKB/Swiss-Prot

Last modified July 9, 2014. Version 168. Feed History...

Clusters with 100%, 90%, 50% identity | Documents (6) | Third-party data text xml rdf/xml gff fasta
to top of pageNames·Attributes·General annotation·Ontologies·Sequence annotation·Sequences·References·Web links·Cross-refs·Entry info·DocumentsCustomize order

Names and origin

Protein namesRecommended 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 names
Name:SFTPB
Synonyms:SFTP3
OrganismHomo sapiens (Human) [Reference proteome]
Taxonomic identifier9606 [NCBI]
Taxonomic lineageEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniHominidaeHomo

Protein attributes

Sequence length381 AA.
Sequence statusComplete.
Sequence processingThe displayed sequence is further processed into a mature form.
Protein existenceEvidence at protein level

General annotation (Comments)

Function

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.

Subunit structure

Homodimer; disulfide-linked. Ref.7

Subcellular location

Secretedextracellular spacesurface film.

Involvement in disease

Pulmonary surfactant metabolism dysfunction 1 (SMDP1) [MIM:265120]: A 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.
Note: The disease is caused by mutations affecting the gene represented in this entry. Ref.10

Respiratory distress syndrome in premature infants (RDS) [MIM:267450]: A 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'.
Note: Disease susceptibility is 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. Ref.12

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).

Sequence similarities

Contains 1 saposin A-type domain.

Contains 3 saposin B-type domains.

Sequence caution

The sequence AAA88099.1 differs from that shown. Reason: Erroneous initiation.

Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Signal peptide1 – 2424 Potential
Propeptide25 – 200176
PRO_0000031647
Chain201 – 27979Pulmonary surfactant-associated protein B
PRO_0000031648
Propeptide280 – 381102
PRO_0000031649

Regions

Domain25 – 6541Saposin A-type
Domain65 – 14783Saposin B-type 1
Domain204 – 28178Saposin B-type 2
Domain295 – 37076Saposin B-type 3

Amino acid modifications

Glycosylation1291N-linked (GlcNAc...) Potential
Glycosylation3111N-linked (GlcNAc...) Potential
Disulfide bond69 ↔ 143 By similarity
Disulfide bond72 ↔ 137 By similarity
Disulfide bond100 ↔ 112 By similarity
Disulfide bond208 ↔ 277 Ref.7
Disulfide bond211 ↔ 271 Ref.7
Disulfide bond235 ↔ 246 Ref.7
Disulfide bond248Interchain Ref.7
Disulfide bond299 ↔ 366 By similarity
Disulfide bond302 ↔ 360 By similarity
Disulfide bond325 ↔ 335 By similarity

Natural variations

Natural variant1311T → I. Ref.3 Ref.11
Corresponds to variant rs1130866 [ dbSNP | Ensembl ].
VAR_006948
Natural variant1761L → F. Ref.3
Corresponds to variant rs3024801 [ dbSNP | Ensembl ].
VAR_013099
Natural variant2281A → I Requires 2 nucleotide substitutions. Ref.7
VAR_006950
Natural variant2281A → R Requires 2 nucleotide substitutions. Ref.2 Ref.5
VAR_006949
Natural variant2361R → C in SMDP1. Ref.10
VAR_036856
Natural variant2721R → H. Ref.3
Corresponds to variant rs3024809 [ dbSNP | Ensembl ].
VAR_013100

Experimental info

Sequence conflict1781L → V in AAA36628. Ref.6
Sequence conflict3181P → L in AAA88099. Ref.5

Secondary structure

........ 381
Helix Strand Turn

Details...

Sequences

Sequence LengthMass (Da)Tools
P07988 [UniParc].

Last modified May 1, 1992. Version 3.
Checksum: 9FD7F66678A35153

FASTA38142,117
        10         20         30         40         50         60 
MAESHLLQWL LLLLPTLCGP GTAAWTTSSL ACAQGPEFWC QSLEQALQCR ALGHCLQEVW 

        70         80         90        100        110        120 
GHVGADDLCQ ECEDIVHILN KMAKEAIFQD TMRKFLEQEC NVLPLKLLMP QCNQVLDDYF 

       130        140        150        160        170        180 
PLVIDYFQNQ TDSNGICMHL GLCKSRQPEP EQEPGMSDPL PKPLRDPLPD PLLDKLVLPV 

       190        200        210        220        230        240 
LPGALQARPG PHTQDLSEQQ FPIPLPYCWL CRALIKRIQA MIPKGALAVA VAQVCRVVPL 

       250        260        270        280        290        300 
VAGGICQCLA ERYSVILLDT LLGRMLPQLV CRLVLRCSMD DSAGPRSPTG EWLPRDSECH 

       310        320        330        340        350        360 
LCMSVTTQAG NSSEQAIPQA MLQACVGSWL DREKCKQFVE QHTPQLLTLV PRGWDAHTTC 

       370        380 
QALGVCGTMS SPLQCIHSPD L 

« Hide

References

« Hide 'large scale' references
[1]"Isolation of a cDNA clone encoding a high molecular weight precursor to a 6-kDa pulmonary surfactant-associated protein."
Jacobs K.A., Phelps D.S., Steinbrink R., Fisch J., Kriz R., Mitsock L., Dougherty J.P., Taeusch H.W., Floros J.
J. Biol. Chem. 262:9808-9811(1987) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [MRNA], PROTEIN SEQUENCE OF 201-214.
Tissue: Lung.
[2]"Structure and organization of the gene encoding human pulmonary surfactant proteolipid SP-B."
Pilot-Matias T.J., Kister S.E., Fox J.L., Kropp K., Glasser S.W., Whitsett J.A.
DNA 8:75-86(1989) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA], VARIANT ARG-228.
[3]SeattleSNPs variation discovery resource
Submitted (JUL-2001) to the EMBL/GenBank/DDBJ databases
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA], VARIANTS ILE-131; PHE-176 AND HIS-272.
[4]"The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC)."
The MGC Project Team
Genome Res. 14:2121-2127(2004) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
Tissue: Brain.
[5]"cDNA and deduced amino acid sequence of human pulmonary surfactant-associated proteolipid SPL(Phe)."
Glasser S.W., Korfhagen T.R., Weaver T., Pilot-Matias T., Fox J.L., Whitsett J.A.
Proc. Natl. Acad. Sci. U.S.A. 84:4007-4011(1987) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [MRNA] OF 99-381, VARIANT ARG-228.
[6]"Use of human surfactant low molecular weight apoproteins in the reconstitution of surfactant biologic activity."
Revak S.D., Merritt T.A., Degryse E., Stefani L., Courtney M., Hallman M., Cochrane C.G.
J. Clin. Invest. 81:826-833(1988) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [MRNA] OF 139-381.
[7]"Human surfactant polypeptide SP-B. Disulfide bridges, C-terminal end, and peptide analysis of the airway form."
Johansson J., Joernvall H., Curstedt T.
FEBS Lett. 301:165-167(1992) [PubMed] [Europe PMC] [Abstract]
Cited for: PROTEIN SEQUENCE OF 201-279, DISULFIDE BONDS, VARIANT ILE-228.
[8]"Conformational mapping of the N-terminal segment of surfactant protein B in lipid using 13C-enhanced Fourier transform infrared spectroscopy."
Gordon L.M., Lee K.Y., Lipp M.M., Zasadzinski J.A., Walther F.J., Sherman M.A., Waring A.J.
J. Pept. Res. 55:330-347(2000) [PubMed] [Europe PMC] [Abstract]
Cited for: STRUCTURE BY FTIR OF 201-225.
[9]"Structure of mini-B, a functional fragment of surfactant protein B, in detergent micelles."
Sarker M., Waring A.J., Walther F.J., Keough K.M., Booth V.
Biochemistry 46:11047-11056(2007) [PubMed] [Europe PMC] [Abstract]
Cited for: STRUCTURE BY NMR OF 208-278.
[10]"Partial deficiency of surfactant protein B in an infant with chronic lung disease."
Ballard P.L., Nogee L.M., Beers M.F., Ballard R.A., Planer B.C., Polk L., deMello D.E., Moxley M.A., Longmore W.J.
Pediatrics 96:1046-1052(1995) [PubMed] [Europe PMC] [Abstract]
Cited for: VARIANT SMDP1 CYS-236.
[11]"Polymorphisms of human SP-A, SP-B, and SP-D genes: association of SP-B Thr131Ile with ARDS."
Lin Z., Pearson C., Chinchilli V., Pietschmann S.M., Luo J., Pison U., Floros J.
Clin. Genet. 58:181-191(2000) [PubMed] [Europe PMC] [Abstract]
Cited for: VARIANT ILE-131.
[12]"Surfactant proteins A and B as interactive genetic determinants of neonatal respiratory distress syndrome."
Haataja R., Raemet M., Marttila R., Hallman M.
Hum. Mol. Genet. 9:2751-2760(2000) [PubMed] [Europe PMC] [Abstract]
Cited for: INVOLVEMENT IN SUSCEPTIBILITY TO RDS.
+Additional computationally mapped references.

Web resources

Cross-references

Sequence databases

EMBL
GenBank
DDBJ
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.
PIRLNHUB. A31361.
RefSeqNP_000533.3. NM_000542.3.
NP_942140.2. NM_198843.2.
UniGeneHs.512690.

3D structure databases

PDBe
RCSB-PDB
PDBj
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[»]
ProteinModelPortalP07988.
SMRP07988. Positions 69-145.
ModBaseSearch...
MobiDBSearch...

Protein-protein interaction databases

STRING9606.ENSP00000345161.

Polymorphism databases

DMDM131418.

Proteomic databases

PaxDbP07988.
PRIDEP07988.

Protocols and materials databases

DNASU6439.
StructuralBiologyKnowledgebaseSearch...

Genome annotation databases

EnsemblENST00000342375; ENSP00000345161; ENSG00000168878.
ENST00000519937; ENSP00000428719; ENSG00000168878.
GeneID6439.
KEGGhsa:6439.

Organism-specific databases

CTD6439.
GeneCardsGC02M085884.
HGNCHGNC:10801. SFTPB.
HPACAB002440.
HPA034820.
MIM178640. gene.
265120. phenotype.
267450. phenotype.
neXtProtNX_P07988.
Orphanet264675. Congenital pulmonary alveolar proteinosis.
70587. Infant acute respiratory distress syndrome.
217563. Neonatal acute respiratory distress with surfactant metabolism deficiency.
PharmGKBPA35713.
GenAtlasSearch...

Phylogenomic databases

eggNOGNOG286450.
HOGENOMHOG000115745.
HOVERGENHBG006905.
InParanoidP07988.
OrthoDBEOG7F24TB.
PhylomeDBP07988.

Gene expression databases

ArrayExpressP07988.
BgeeP07988.
CleanExHS_SFTPB.
GenevestigatorP07988.

Family and domain databases

Gene3D1.10.225.10. 3 hits.
InterProIPR003119. SapA.
IPR007856. SapB_1.
IPR008138. SapB_2.
IPR008373. Saposin.
IPR011001. Saposin-like.
IPR008139. SaposinB.
[Graphical view]
PfamPF02199. SapA. 1 hit.
PF05184. SapB_1. 1 hit.
PF03489. SapB_2. 2 hits.
[Graphical view]
PRINTSPR01797. SAPOSIN.
SMARTSM00162. SAPA. 1 hit.
SM00741. SapB. 3 hits.
[Graphical view]
SUPFAMSSF47862. SSF47862. 3 hits.
PROSITEPS51110. SAP_A. 1 hit.
PS50015. SAP_B. 3 hits.
[Graphical view]
ProtoNetSearch...

Other

ChiTaRSSFTPB. human.
EvolutionaryTraceP07988.
GeneWikiPulmonary_surfactant-associated_protein_B.
GenomeRNAi6439.
NextBio25021.
PMAP-CutDBP07988.
PROP07988.
SOURCESearch...

Entry information

Entry namePSPB_HUMAN
AccessionPrimary (citable) accession number: P07988
Secondary accession number(s): Q96R04
Entry history
Integrated into UniProtKB/Swiss-Prot: August 1, 1988
Last sequence update: May 1, 1992
Last modified: July 9, 2014
This is version 168 of the entry and version 3 of the sequence. [Complete history]
Entry statusReviewed (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.

Relevant documents

SIMILARITY comments

Index of protein domains and families

PDB cross-references

Index of Protein Data Bank (PDB) cross-references

MIM cross-references

Online Mendelian Inheritance in Man (MIM) cross-references in UniProtKB/Swiss-Prot

Human polymorphisms and disease mutations

Index of human polymorphisms and disease mutations

Human entries with polymorphisms or disease mutations

List of human entries with polymorphisms or disease mutations

Human chromosome 2

Human chromosome 2: entries, gene names and cross-references to MIM