Home Page for S100B

S100B

Primary information about S100B:
Basic chemical and physical information	Basic biological information	Basic genomic information	Metal ion binding constants	Interspecies sequence alignment	Information on function
Summary of structural studies	Information on the conformational change	List of available structures	Information about mutations	References about S100B	Other web resources about S100B
Additional information about S100B:
Information about the evolutionary relationship of S100B to other proteins

Basic Information

Basic Chemical and Physical Information:
Additional names and abbreviations:	S100B: neurite extension factor (NEF)
Isoforms:	No information about isoforms is stored in the database
Yeast Protein Database Entries:	No links to the YPD are stored in the database

Number of amino acids:	91 (all species) View a list of all sources stored in the database
Molecular weight:	10.537 kD (Bos taurus) - 10.613 kD (Rattus norvegicus) View a list of all sources stored in the database
pI:	not yet available in the data library
Number of functional calcium binding sites:	Bos taurus: 2 (InfoCard)
Macroscopic calcium binding constants:	not yet available in the data library
Other metal binding constants:	not yet available in the data library
Protein stability:	not yet available in the data library
Post-translational modifications:	not yet available in the data library

Basic Biological Information:
Source organisms:	Bos taurus, Homo sapiens, Mus musculus, Rattus norvegicus View an annotated list of all sources stored in the database
Tissues:	Bos taurus: brain (InfoCard) Bos taurus: adipose tissue (InfoCard) Rattus norvegicus: brain (InfoCard) Rattus norvegicus: trachea (InfoCard) Rattus norvegicus: pituitary gland (InfoCard) Rattus norvegicus: skin (InfoCard)
Subcellular localization:	not yet available in the data library
Regulation:	not yet available in the data library

Genomic Information:
GenBank entries:	View a list of GenBank entries stored in the database
Gene length:	not yet available in the data library
Gene structure:	Homo sapiens, expressed: GenBank codes , J05600; 2 introns (InfoCard) Rattus norvegicus, expressed: GenBank codes S53522, S53527; 2 introns (InfoCard) Mus musculus, expressed: GenBank codes , L22144; 2 introns (InfoCard)
Promoter:	not yet available in the data library
Gene copies:	not yet available in the data library
Alleles:	no alleles are currently stored in the data library
Chromosomal localization:	Homo sapiens, expressed (GenBank code J05600): q22.2-22.3 region of chromosome 21 (in the Down syndrome region) (InfoCard)

Interspecies Sequence Alignment


 
                  |-helixA-|--loop1------|helixB|
                  En**nn**nX**Y*Z**#Ix**zn**nn*n

HUMAN   : SELEKAMVALIDVFHQYSGREGDKHKLKKSELKELINNELSHFLEEIKEQE
MOUSE   : SELEKAMVALIDVFHQYSGREGDKHKLKKSELKELINNELSHFLEEIKEQE
RAT     : SELEKAMVALIDVFHQYSGREGDKHKLKKSELKELINNELSHFLEEIKEQE
BOVINE  : SELEKAVVALIDVFHQYSGREGDKHKLKKSELKELINNELSHFLEEIKEQE

         |-helixC-|--loop2-----|helixD| 
          En**nn**nX*Y*ZG#Ix**zn**nn*n

HUMAN   : VVDKVMETLDNDGDGECDFQEFMAFVAMVTTACHEFFEHE
MOUSE   : VVDKVMETLDEDGDGECDFQEFMAFVAMVTTACHEFFEHE
RAT     : VVDKVMETLDEDGDGECDFQEFMAFVSMVTTACHEFFEHE
BOVINE  : VVDKVMETLDSDGDGECDFQEFMAFVAMITTACHEFFEHE

Sequence alignment of the entire S100 subfamily

Functional Information:

General information:

no general functional information is currently stored in the database

Biological roles:

neurite extension
biochemical evidence in Gallus gallus: Recombinant bovine S100B was found to stimulate neurite outgrowth and enhance cell maintenance in cultures of chick embryonic cerebral cortex neurons. This effect is reduced if the neurons are preincubated with anti-S100B antibodies. (InfoCard)
melanoma cell proliferation: may regulate this process
cell biological evidence in Homo sapiens: S100B stimulates growth of cultured human melanoma cells (InfoCard)
microtubule assembly: inhibits this process
biochemical evidence in Rattus norvegicus: Purified S100B inhibits DMSO-induced assembly of tubulin (InfoCard)

Disease states:

Down syndrome
genetic evidence : S100B is found in large amounts in the nervous system, and is on chromosome 21, which is present in three copies in Down Syndrome patients (InfoCard)
epilepsy
immunocytochemical or immunohistochemical evidence : ELISA experiments show levels of S100B to be fivefold higher in temporal lobe tissues from epileptics compared to levels in controls (InfoCard)
Alzheimer's disease
in vivo evidence : Levels of S100B mRNA, protein, and specific neurotrophic activity were elevated in extracts from Alzheimer's patients' autopsy samples compared to levels in aged control samples (InfoCard)

Target molecules:

S100A1
biochemical evidence for interaction in Bos taurus: S100A1 and S100B can be isolated as a complex from bovine brain (InfoCard)
p53
biochemical evidence for interaction in Bos taurus: p53 was shown to bind to S100B in a calcium-dependent manner by affinity chromatography: p53 is retained on a S100B-sepharose column in the presence of calcium, and eluted by the addition of EGTA (InfoCard)
spectroscopic evidence for interaction in Rattus norvegicus: Fluorescence and nuclear magnetic resonance spectra of S100B showed specific changes upon the addition of p53 (InfoCard)
effect of interaction in Bos taurus: S100B binding to p53 inhibits phosphorylation of p53 by protein kinase C (InfoCard)
effect of interaction in Bos taurus: S100B binding to p53 inhibits oligomerization of p53 (InfoCard)
phosphoglucomutase
biochemical evidence for interaction in Bos taurus: Affinity chromatography demonstrates that phosphoglucomutase binds to S100B-Sepharose, and S100B binds to phosphoglucomutase-Sepharose in a calcium-dependent manner (InfoCard)
effect of interaction in Bos taurus: S100B stimulates phosphoglucomutase activity in a calcium-dependent manner (InfoCard)

Structural Information:

Calcium-coordination:
Bos taurus:	EF1 ; X = S18 O; Y = E21 O; Z = D23 O; -X = H₂O; -Y = K26 O; -Z1 = E31 OE1; -Z2 = E31 OE2 EF2 ; X = D61 OD; Y = D63 OD; Z = D65 OD; -X = H₂O; -Y = E67 O; -Z1 = E72 OE1; -Z2 = E72 OE2 (InfoCard)

Nature of the conformational changes:
not yet available in the data library

Secondary structure: (as reported in the PDB file and its accompanying reference)
Bos taurus, two calcium ions bound state:	Helices: helix 1: 2 - 18, helix 2: 29 - 39, helix 3: 50 - 60, helix 4: 70 - 86 (pdb code 1MHO: InfoCard)

Additional structural information:
View a table of interhelical angles from various structures View a table of hydrogen bonds observed in various structures

Available structures: (follow the links from the PDB code to the retrieve the PDB files)
Apo Structures:	1CFP: Bos taurus, homodimer, pH 6.3 NMR solution structure, 25 models, 8.94 restraints per residue (InfoCard) 1SYM: Rattus norvegicus, homodimer, NMR solution structure, 20 models, 15.16 restraints per residue (InfoCard)
Calcium Loaded Structures:	1QLK: Rattus norvegicus, homodimer, pH 6.5 NMR solution structure, 20 models, 11.73 restraints per residue 2 Ca ions bound (InfoCard) 1UWO: Homo sapiens, homodimer, pH 7.05 NMR solution structure, 20 models, 14.14 restraints per residue 2 Ca ions bound (InfoCard) 1MHO: Bos taurus, homodimer, pH 7.5 Crystal structure, 2 angstrom resolution, R-value = 19.4, R-free = 28.5 2 Ca ions bound (InfoCard)

Information about mutants:

no mutants are currently stored in the database