2OTC

ORNITHINE TRANSCARBAMOYLASE COMPLEXED WITH N-(PHOSPHONACETYL)-L-ORNITHINE

2OTC の概要

• エントリーDOI: 10.2210/pdb2otc/pdb
• 分子名称: ORNITHINE CARBAMOYLTRANSFERASE, N-(PHOSPHONOACETYL)-L-ORNITHINE (3 entities in total)
• 機能のキーワード: transferase, otcase, ornithine, transcarbamoylase, arginine synthesis, urea cycle
• 由来する生物種: Escherichia coli BL21(DE3)
• 細胞内の位置: Cytoplasm (Probable): P04391
• タンパク質・核酸の鎖数: 9
• 化学式量合計: 334288.18

構造登録者

Ha, Y.,Allewell, N.M. (登録日: 1997-06-15, 公開日: 1998-06-17, 最終更新日: 2024-05-22)

主引用文献

Ha, Y.,McCann, M.T.,Tuchman, M.,Allewell, N.M.
Substrate-induced conformational change in a trimeric ornithine transcarbamoylase.
Proc.Natl.Acad.Sci.USA, 94:9550-9555, 1997

PubMed Abstract: 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.

PubMed: 9275160
DOI: 10.1073/pnas.94.18.9550

実験手法

X-RAY DIFFRACTION (2.8 Å)