1gh4
From Proteopedia
(New page: 200px<br /><applet load="1gh4" size="450" color="white" frame="true" align="right" spinBox="true" caption="1gh4, resolution 1.9Å" /> '''Structure of the trip...) |
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| - | [[Image:1gh4.jpg|left|200px]]<br /><applet load="1gh4" size=" | + | [[Image:1gh4.jpg|left|200px]]<br /><applet load="1gh4" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1gh4, resolution 1.9Å" /> | caption="1gh4, resolution 1.9Å" /> | ||
'''Structure of the triple mutant (K56M, K120M, K121M) of phospholipase A2'''<br /> | '''Structure of the triple mutant (K56M, K120M, K121M) of phospholipase A2'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Phospholipase A(2) catalyses hydrolysis of the ester bond at the C2 | + | Phospholipase A(2) catalyses hydrolysis of the ester bond at the C2 position of 3-sn-phosphoglycerides. Here we report the 1.9A resolution crystal structure of the triple mutant K56,120,121M of bovine pancreatic phospholipase A(2). The structure was solved by molecular replacement method using the orthorhombic form of the recombinant phospholipase A(2). The final protein model contains all the 123 amino acid residues, two calcium ions, 125 water molecules and one 2-methyl-2-4-pentanediol molecule. The model has been refined to a crystallographic R-factor of 19.6% (R(free) of 25.9%) for all data between 14.2A and 1.9A. The residues 62-66, which are in a surface loop, are always disordered in the structures of bovine pancreatic phospholipase A(2) and its mutants. It is interesting to note that the residues 62-66 in the present structure is ordered and the conformation varies substantially from those in the previously published structures of this enzyme. An unexpected and interesting observation in the present structure is that, in addition to the functionally important calcium ion in the active site, one more calcium ion is found near the N terminus. Detailed structural analyses suggest that binding of the second calcium ion could be responsible for the conformational change and the ordering of the surface loop. Furthermore, the results suggest a structural reciprocity between the k(cat)(*) allosteric site and surface loop at the i-face, which represents a newly identified structural property of secreted phospholipase A(2). |
==About this Structure== | ==About this Structure== | ||
| - | 1GH4 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus] with CA and MPD as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Phospholipase_A(2) Phospholipase A(2)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.1.4 3.1.1.4] Full crystallographic information is available from [http:// | + | 1GH4 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus] with <scene name='pdbligand=CA:'>CA</scene> and <scene name='pdbligand=MPD:'>MPD</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Phospholipase_A(2) Phospholipase A(2)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.1.4 3.1.1.4] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1GH4 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Sekar, K.]] | [[Category: Sekar, K.]] | ||
| - | [[Category: Tsai, M | + | [[Category: Tsai, M D.]] |
[[Category: Velmurugan, D.]] | [[Category: Velmurugan, D.]] | ||
[[Category: CA]] | [[Category: CA]] | ||
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[[Category: triple mutant]] | [[Category: triple mutant]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:50:01 2008'' |
Revision as of 10:50, 21 February 2008
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Structure of the triple mutant (K56M, K120M, K121M) of phospholipase A2
Overview
Phospholipase A(2) catalyses hydrolysis of the ester bond at the C2 position of 3-sn-phosphoglycerides. Here we report the 1.9A resolution crystal structure of the triple mutant K56,120,121M of bovine pancreatic phospholipase A(2). The structure was solved by molecular replacement method using the orthorhombic form of the recombinant phospholipase A(2). The final protein model contains all the 123 amino acid residues, two calcium ions, 125 water molecules and one 2-methyl-2-4-pentanediol molecule. The model has been refined to a crystallographic R-factor of 19.6% (R(free) of 25.9%) for all data between 14.2A and 1.9A. The residues 62-66, which are in a surface loop, are always disordered in the structures of bovine pancreatic phospholipase A(2) and its mutants. It is interesting to note that the residues 62-66 in the present structure is ordered and the conformation varies substantially from those in the previously published structures of this enzyme. An unexpected and interesting observation in the present structure is that, in addition to the functionally important calcium ion in the active site, one more calcium ion is found near the N terminus. Detailed structural analyses suggest that binding of the second calcium ion could be responsible for the conformational change and the ordering of the surface loop. Furthermore, the results suggest a structural reciprocity between the k(cat)(*) allosteric site and surface loop at the i-face, which represents a newly identified structural property of secreted phospholipase A(2).
About this Structure
1GH4 is a Single protein structure of sequence from Bos taurus with and as ligands. Active as Phospholipase A(2), with EC number 3.1.1.4 Full crystallographic information is available from OCA.
Reference
Observation of additional calcium ion in the crystal structure of the triple mutant K56,120,121M of bovine pancreatic phospholipase A2., Rajakannan V, Yogavel M, Poi MJ, Jeyaprakash AA, Jeyakanthan J, Velmurugan D, Tsai MD, Sekar K, J Mol Biol. 2002 Dec 6;324(4):755-62. PMID:12460575
Page seeded by OCA on Thu Feb 21 12:50:01 2008
Categories: Bos taurus | Phospholipase A(2) | Single protein | Sekar, K. | Tsai, M D. | Velmurugan, D. | CA | MPD | Alpha helix | Beta sheet | Triple mutant
