2otc
From Proteopedia
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| - | + | {{STRUCTURE_2otc| PDB=2otc | SCENE= }} | |
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'''ORNITHINE TRANSCARBAMOYLASE COMPLEXED WITH N-(PHOSPHONACETYL)-L-ORNITHINE''' | '''ORNITHINE TRANSCARBAMOYLASE COMPLEXED WITH N-(PHOSPHONACETYL)-L-ORNITHINE''' | ||
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[[Category: Allewell, N M.]] | [[Category: Allewell, N M.]] | ||
[[Category: Ha, Y.]] | [[Category: Ha, Y.]] | ||
| - | [[Category: | + | [[Category: Arginine synthesis]] |
| - | [[Category: | + | [[Category: Ornithine]] |
| - | [[Category: | + | [[Category: Otcase]] |
| - | [[Category: | + | [[Category: Transcarbamoylase]] |
| - | [[Category: | + | [[Category: Transferase]] |
| - | [[Category: | + | [[Category: Urea cycle]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun May 4 11:36:54 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 08:36, 4 May 2008
ORNITHINE TRANSCARBAMOYLASE COMPLEXED WITH N-(PHOSPHONACETYL)-L-ORNITHINE
Overview
The crystal structure of Escherichia coli ornithine transcarbamoylase (OTCase, EC 2.1.3.3) complexed with the bisubstrate analog N-(phosphonacetyl)-L-ornithine (PALO) has been determined at 2.8-A resolution. This research on the structure of a transcarbamoylase catalytic trimer with a substrate analog bound provides new insights into the linkages between substrate binding, protein-protein interactions, and conformational change. The structure was solved by molecular replacement with the Pseudomonas aeruginosa catabolic OTCase catalytic trimer (Villeret, V., Tricot, C., Stalon, V. & Dideberg, O. (1995) Proc. Natl. Acad. Sci. USA 92, 10762-10766; Protein Data Bank reference pdb 1otc) as the model and refined to a crystallographic R value of 21.3%. Each polypeptide chain folds into two domains, a carbamoyl phosphate binding domain and an L-ornithine binding domain. The bound inhibitor interacts with the side chains and/or backbone atoms of Lys-53, Ser-55, Thr-56, Arg-57, Thr-58, Arg-106, His-133, Asn-167, Asp-231, Met-236, Leu-274, Arg-319 as well as Gln-82 and Lys-86 from an adjacent chain. Comparison with the unligated P. aeruginosa catabolic OTCase structure indicates that binding of the substrate analog results in closure of the two domains of each chain. As in E. coli aspartate transcarbamoylase, the 240s loop undergoes the largest conformational change upon substrate binding. The clinical implications for human OTCase deficiency are discussed.
About this Structure
2OTC is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
Substrate-induced conformational change in a trimeric ornithine transcarbamoylase., Ha Y, McCann MT, Tuchman M, Allewell NM, Proc Natl Acad Sci U S A. 1997 Sep 2;94(18):9550-5. PMID:9275160 Page seeded by OCA on Sun May 4 11:36:54 2008
