Sandbox Reserved 954: Difference between revisions
From Proteopedia
Jump to navigationJump to search
Léo Alcapia (talk | contribs) No edit summary |
Léo Alcapia (talk | contribs) No edit summary |
||
| (4 intermediate revisions by 2 users not shown) | |||
| Line 9: | Line 9: | ||
Serpins are a superfamily of proteins wich are functionally distinct but structurally conserved. <ref>JBC Papers in Press. Published on July 2, 2001 as Manuscript R100016200 THE SERPINS ARE AN EXPANDING SUPERFAMILY OF | Serpins are a superfamily of proteins wich are functionally distinct but structurally conserved. <ref>JBC Papers in Press. Published on July 2, 2001 as Manuscript R100016200 THE SERPINS ARE AN EXPANDING SUPERFAMILY OF | ||
STRUCTURALLY SIMILAR BUT FUNCTIONALLY DIVERSE | STRUCTURALLY SIMILAR BUT FUNCTIONALLY DIVERSE PROTEINS, http://www.jbc.org/content/early/2001/07/02/jbc.R100016200.full.pdf DOI : 2001/07/02/jbc.R100016200.full.pdf </ref> | ||
SerpinB3 means serin protease inhibitor, clade B (for ovalbumin), member 3. The particularity of serpin B3 is to target proteases which have a nucleophilic cysteine instead of serine in their catalytic site. | SerpinB3 means serin protease inhibitor, clade B (for ovalbumin), member 3. The particularity of serpin B3 is to target proteases which have a nucleophilic cysteine instead of serine in their catalytic site. | ||
SCCA1 is a <scene name='60/604473/Trimeric/1'>trimeric protein</scene><ref> PMID : 19166818 </ref>. <scene name='60/604473/One_subunit/1'>One subunit</scene> has three β sheets termed <scene name='60/604473/A_beta_sheet/3'>A (7 stranded)</scene>, <scene name='60/604473/B_beta_sheet/2'>B (5 stranded)</scene> and <scene name='60/604473/C_beta_sheet/2'>C (6 stranded)</scene> and <scene name='60/604473/Alpha_helices/1'>11 α helices (hA to hK)</scene> <ref>Gary A. Silverman1*, Phillip I. Bird2 | SCCA1 is a <scene name='60/604473/Trimeric/1'>trimeric protein</scene><ref> PMID : 19166818 </ref>. <scene name='60/604473/One_subunit/1'>One subunit</scene> has three β sheets termed <scene name='60/604473/A_beta_sheet/3'>A (7 stranded)</scene>, <scene name='60/604473/B_beta_sheet/2'>B (5 stranded)</scene> and <scene name='60/604473/C_beta_sheet/2'>C (6 stranded)</scene> and <scene name='60/604473/Alpha_helices/1'>11 α helices (hA to hK)</scene> <ref>Gary A. Silverman1*, Phillip I. Bird2 | ||
| Line 30: | Line 30: | ||
===Conformational changes of serpins=== | ===Conformational changes of serpins=== | ||
The inhibitory members of serpin family undergo an unusual conformational change, the Stressed to Relaxed transition. This structural transition causes the <scene name='60/604473/The_rcl_loop_scene/3'>RCL</scene> insertion into <scene name='60/604473/A_beta_sheet/3'>A β-sheet</scene> thereby the <scene name='60/604473/The_rcl_loop_scene/3'>RCL</scene> forms an extra β strand. The serpin conformational change is essential for the inhibitor mechanism of proteases. <scene name='60/604473/Rcl_insertion_into_beta_sheet/1'>Some amino-acids of RCL</scene> wich belong to a consensus sequence for inhibitory serpins are thought to permit the insertion of the <scene name='60/604473/The_rcl_loop_scene/3'>RCL</scene> into the <scene name='60/604473/A_beta_sheet/3'>A β-sheet</scene>.<ref> James C Whisstocka, 2, Richard Skinnera, 2, Robin W Carrella, Arthur M Leska, Conformational changes in serpins: I. the native and cleaved conformations of α1-antitrypsin1, http://www.sciencedirect.com/science/article/pii/S0022283699935209 DOI: | The inhibitory members of serpin family undergo an unusual conformational change, the Stressed to Relaxed transition. This structural transition causes the <scene name='60/604473/The_rcl_loop_scene/3'>RCL</scene> insertion into <scene name='60/604473/A_beta_sheet/3'>A β-sheet</scene> thereby the <scene name='60/604473/The_rcl_loop_scene/3'>RCL</scene> forms an extra β strand. The serpin conformational change is essential for the inhibitor mechanism of proteases. <scene name='60/604473/Rcl_insertion_into_beta_sheet/1'>Some amino-acids of RCL</scene> wich belong to a consensus sequence for inhibitory serpins are thought to permit the insertion of the <scene name='60/604473/The_rcl_loop_scene/3'>RCL</scene> into the <scene name='60/604473/A_beta_sheet/3'>A β-sheet</scene>.<ref> James C Whisstocka, 2, Richard Skinnera, 2, Robin W Carrella, Arthur M Leska, Conformational changes in serpins: I. the native and cleaved conformations of α1-antitrypsin1, http://www.sciencedirect.com/science/article/pii/S0022283699935209 DOI:10.1006/jmbi.1999.3520</ref>Key regions able to control and modulate the conformational change of RCL. The hinge which is the <scene name='60/604473/P9-p15/1'>P15-P9 portion of the RCL</scene> is responsible for the mobility which is essential during the conformational change in the Stress to Relax transition. The breach is situated in the top of the <scene name='60/604473/A_beta_sheet/3'>β-sheet</scene>. It is located at the point of initial insertion of the <scene name='60/604473/The_rcl_loop_scene/3'>RCL</scene> into the <scene name='60/604473/A_beta_sheet/3'>A β-sheet</scene>. The shutter is next to the <scene name='60/604473/A_beta_sheet/3'>A β-sheet</scene>. It facilitates the beta-sheet opening and accept the conserved hinge of the <scene name='60/604473/The_rcl_loop_scene/3'>RCL</scene> as it insert. The gate is fully inserted into the <scene name='60/604473/A_beta_sheet/3'>A β-sheet</scene> without cleavage, the <scene name='60/604473/The_rcl_loop_scene/3'>RCL</scene> has to pass around the β-turn linking strands. | ||
[[Image:Structure region.jpg|center|thumbnail|300px|'''Key regions able to control and modulate the conformational change of RCL''']] | |||
[[Image:Structure region.jpg|center|thumbnail|300px|'''Key regions able to control and modulate the conformational change of RCL<ref>PMID :11116082</ref>''']] | |||
==Main SCCA1 function== | ==Main SCCA1 function== | ||
| Line 112: | Line 113: | ||
= References = | = References = | ||
<references/> | <references/> | ||
