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1qxp
From Proteopedia
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[[Image:1qxp.jpg|left|200px]] | [[Image:1qxp.jpg|left|200px]] | ||
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'''Crystal Structure of a mu-like calpain''' | '''Crystal Structure of a mu-like calpain''' | ||
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[[Category: Pal, G P.]] | [[Category: Pal, G P.]] | ||
[[Category: Veyra, T D.]] | [[Category: Veyra, T D.]] | ||
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| - | + | [[Category: M-calpain]] | |
| - | [[Category: | + | [[Category: Mu-calpain]] |
| - | [[Category: | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 06:49:46 2008'' |
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Revision as of 03:49, 3 May 2008
Crystal Structure of a mu-like calpain
Overview
The two Ca2+-dependent cysteine proteases, micro- and m-calpain, are involved in various Ca2+-linked signal pathways but differ markedly in their Ca2+ requirements for activation. We have determined the structure of a micro-like calpain, which has 85% micro-calpain sequence (the first 48 and the last 62 residues of the large subunit are those from m-calpain) and a low Ca2+ requirement. This construct was used because micro-calpain itself is too poorly expressed. The structure of micro-like calpain is very similar in overall fold to that of m-calpain as expected, but differs significantly in two aspects. In comparison with m-calpain, the catalytic triad residues in micro-like calpain, His and Cys, are much closer together in the absence of Ca2+, and significant portions of the Ca2+ binding EF-hand motifs are disordered and more flexible. These structural differences imply that Ca2+-free micro-calpain may represent a partially activated structure, requiring lower Ca2+ concentration to trigger its activation.
About this Structure
1QXP is a Single protein structure of sequence from Rattus norvegicus. Full crystallographic information is available from OCA.
Reference
Crystal structure of a micro-like calpain reveals a partially activated conformation with low Ca2+ requirement., Pal GP, De Veyra T, Elce JS, Jia Z, Structure. 2003 Dec;11(12):1521-6. PMID:14656436 Page seeded by OCA on Sat May 3 06:49:46 2008
