2oct

From Proteopedia

Stefin B (Cystatin B) tetramer

PDB ID 2oct

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Structural highlights

2oct is a 2 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 1.4Å
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Disease

CYTB_HUMAN Defects in CSTB are the cause of progressive myoclonic epilepsy type 1 (EPM1) [MIM:254800. EPM1 is an autosomal recessive disorder characterized by severe, stimulus-sensitive myoclonus and tonic-clonic seizures. The onset, occurring between 6 and 13 years of age, is characterized by convulsions. Myoclonus begins 1 to 5 years later. The twitchings occur predominantly in the proximal muscles of the extremities and are bilaterally symmetrical, although asynchronous. At first small, they become late in the clinical course so violent that the victim is thrown to the floor. Mental deterioration and eventually dementia develop.^[1]

Function

CYTB_HUMAN This is an intracellular thiol proteinase inhibitor. Tightly binding reversible inhibitor of cathepsins L, H and B.

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

Here we present the tetrameric structure of stefin B, which is the result of a process by which two domain-swapped dimers of stefin B are transformed into tetramers. The transformation involves a previously unidentified process of extensive intermolecular contacts, termed hand shaking, which occurs concurrently with trans to cis isomerization of proline 74. This proline residue is widely conserved throughout the cystatin superfamily, a member of which, human cystatin C, is the key protein in cerebral amyloid angiopathy. These results are consistent with the hypothesis that isomerization of proline residues can play a decisive role in amyloidogenesis.

Essential role of proline isomerization in stefin B tetramer formation.,Jenko Kokalj S, Guncar G, Stern I, Morgan G, Rabzelj S, Kenig M, Staniforth RA, Waltho JP, Zerovnik E, Turk D J Mol Biol. 2007 Mar 9;366(5):1569-79. Epub 2006 Dec 16. PMID:17217964^[2]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Lalioti MD, Mirotsou M, Buresi C, Peitsch MC, Rossier C, Ouazzani R, Baldy-Moulinier M, Bottani A, Malafosse A, Antonarakis SE. Identification of mutations in cystatin B, the gene responsible for the Unverricht-Lundborg type of progressive myoclonus epilepsy (EPM1). Am J Hum Genet. 1997 Feb;60(2):342-51. PMID:9012407
↑ Jenko Kokalj S, Guncar G, Stern I, Morgan G, Rabzelj S, Kenig M, Staniforth RA, Waltho JP, Zerovnik E, Turk D. Essential role of proline isomerization in stefin B tetramer formation. J Mol Biol. 2007 Mar 9;366(5):1569-79. Epub 2006 Dec 16. PMID:17217964 doi:10.1016/j.jmb.2006.12.025