1qxp
From Proteopedia
(New page: 200px<br /><applet load="1qxp" size="450" color="white" frame="true" align="right" spinBox="true" caption="1qxp, resolution 2.80Å" /> '''Crystal Structure of...) |
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| - | [[Image:1qxp.jpg|left|200px]]<br /><applet load="1qxp" size=" | + | [[Image:1qxp.jpg|left|200px]]<br /><applet load="1qxp" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1qxp, resolution 2.80Å" /> | caption="1qxp, resolution 2.80Å" /> | ||
'''Crystal Structure of a mu-like calpain'''<br /> | '''Crystal Structure of a mu-like calpain'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The two Ca2+-dependent cysteine proteases, micro- and m-calpain, are | + | 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== | ==About this Structure== | ||
| - | 1QXP is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Rattus_norvegicus Rattus norvegicus]. Active as [http://en.wikipedia.org/wiki/Calpain-1 Calpain-1], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.22.52 3.4.22.52] Full crystallographic information is available from [http:// | + | 1QXP is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Rattus_norvegicus Rattus norvegicus]. Active as [http://en.wikipedia.org/wiki/Calpain-1 Calpain-1], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.22.52 3.4.22.52] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QXP OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Rattus norvegicus]] | [[Category: Rattus norvegicus]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Elce, J | + | [[Category: Elce, J S.]] |
[[Category: Jia, Z.]] | [[Category: Jia, Z.]] | ||
| - | [[Category: Pal, G | + | [[Category: Pal, G P.]] |
| - | [[Category: Veyra, T | + | [[Category: Veyra, T D.]] |
[[Category: ca(2+) requirement]] | [[Category: ca(2+) requirement]] | ||
[[Category: catalytic triad]] | [[Category: catalytic triad]] | ||
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[[Category: mu-calpain]] | [[Category: mu-calpain]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:44:49 2008'' |
Revision as of 12:44, 21 February 2008
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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. Active as Calpain-1, with EC number 3.4.22.52 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
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