4cms
From Proteopedia
(New page: 200px<br /> <applet load="4cms" size="450" color="white" frame="true" align="right" spinBox="true" caption="4cms, resolution 2.2Å" /> '''X-RAY ANALYSES OF AS...) |
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caption="4cms, resolution 2.2Å" /> | caption="4cms, resolution 2.2Å" /> | ||
'''X-RAY ANALYSES OF ASPARTIC PROTEINASES IV. STRUCTURE AND REFINEMENT AT 2.2 ANGSTROMS RESOLUTION OF BOVINE CHYMOSIN'''<br /> | '''X-RAY ANALYSES OF ASPARTIC PROTEINASES IV. STRUCTURE AND REFINEMENT AT 2.2 ANGSTROMS RESOLUTION OF BOVINE CHYMOSIN'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The structure of calf chymosin (EC 3.4.23.3), the aspartic proteinase from | + | The structure of calf chymosin (EC 3.4.23.3), the aspartic proteinase from the gastric mucosa, was solved using the technique of molecular replacement. We describe the use of different search models based on distantly related fungal aspartic proteinases and investigate the effect of using only structurally conserved regions. The structure has been refined to a crystallographic R-factor of 17% at 2.2 A resolution with an estimated co-ordinate error of 0.21 A. In all, 136 water molecules have been located of which eight are internal. The structure of chymosin resembles that of pepsin and other aspartic proteinases. However, there is a considerable rearrangement of the active-site "flap" and, in particular, Tyr75 (pepsin numbering), which forms part of the specificity pockets S1 and S1'. This is probably a consequence of crystal packing. Electrostatic interactions on the edge of the substrate binding cleft appear to account for the restricted proteolysis of the natural substrate kappa-casein by chymosin. The local environment of invariant residues is examined, showing that structural constraints and side-chain hydrogen bonding can play an important role in the conservation of particular amino acids. |
==About this Structure== | ==About this Structure== | ||
| - | 4CMS is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus]. The following page contains interesting information on the relation of 4CMS with [[http://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/pdb12_1.html Pepsin]]. Active as [http://en.wikipedia.org/wiki/Chymosin Chymosin], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.23.4 3.4.23.4] Full crystallographic information is available from [http:// | + | 4CMS is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus]. The following page contains interesting information on the relation of 4CMS with [[http://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/pdb12_1.html Pepsin]]. Active as [http://en.wikipedia.org/wiki/Chymosin Chymosin], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.23.4 3.4.23.4] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4CMS OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Andreeva, N.]] | [[Category: Andreeva, N.]] | ||
| - | [[Category: Blundell, T | + | [[Category: Blundell, T L.]] |
[[Category: Frazao, C.]] | [[Category: Frazao, C.]] | ||
[[Category: Khan, G.]] | [[Category: Khan, G.]] | ||
[[Category: Newman, M.]] | [[Category: Newman, M.]] | ||
[[Category: Safro, M.]] | [[Category: Safro, M.]] | ||
| - | [[Category: Tickle, I | + | [[Category: Tickle, I J.]] |
[[Category: Zdanov, A.]] | [[Category: Zdanov, A.]] | ||
[[Category: hydrolase (acid proteinase)]] | [[Category: hydrolase (acid proteinase)]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 19:12:58 2008'' |
Revision as of 17:12, 21 February 2008
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X-RAY ANALYSES OF ASPARTIC PROTEINASES IV. STRUCTURE AND REFINEMENT AT 2.2 ANGSTROMS RESOLUTION OF BOVINE CHYMOSIN
Overview
The structure of calf chymosin (EC 3.4.23.3), the aspartic proteinase from the gastric mucosa, was solved using the technique of molecular replacement. We describe the use of different search models based on distantly related fungal aspartic proteinases and investigate the effect of using only structurally conserved regions. The structure has been refined to a crystallographic R-factor of 17% at 2.2 A resolution with an estimated co-ordinate error of 0.21 A. In all, 136 water molecules have been located of which eight are internal. The structure of chymosin resembles that of pepsin and other aspartic proteinases. However, there is a considerable rearrangement of the active-site "flap" and, in particular, Tyr75 (pepsin numbering), which forms part of the specificity pockets S1 and S1'. This is probably a consequence of crystal packing. Electrostatic interactions on the edge of the substrate binding cleft appear to account for the restricted proteolysis of the natural substrate kappa-casein by chymosin. The local environment of invariant residues is examined, showing that structural constraints and side-chain hydrogen bonding can play an important role in the conservation of particular amino acids.
About this Structure
4CMS is a Single protein structure of sequence from Bos taurus. The following page contains interesting information on the relation of 4CMS with [Pepsin]. Active as Chymosin, with EC number 3.4.23.4 Full crystallographic information is available from OCA.
Reference
X-ray analyses of aspartic proteinases. IV. Structure and refinement at 2.2 A resolution of bovine chymosin., Newman M, Safro M, Frazao C, Khan G, Zdanov A, Tickle IJ, Blundell TL, Andreeva N, J Mol Biol. 1991 Oct 20;221(4):1295-309. PMID:1942052
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