Nitric Oxide Synthases: Structure, Function, and Control

Autor: John C. Salerno, Susan M. E. Smith, Christa Brown, Dawn E. Harris
Rok vydání: 1998
Předmět:
Zdroj: Oxygen Homeostasis and Its Dynamics ISBN: 9784431684787
DOI: 10.1007/978-4-431-68476-3_36
Popis: Nitric oxide synthases are large modular enzymes that produce NO and citrulline from arginine at the expense of NADPH and O2. We have modeled the reductase region, which corresponds roughly to the C-terminal half of the molecule, using the available crystal structures of flavodoxin (FMN-binding domain) and ferredoxin NADPH reductase (FAD- and NADPH-binding domains). This has enabled us to identify important sequence regions that interact with cofactors and to show that the N-terminal boundary of the reductase domain extends to within a few residues of the CaM-binding site. A large (40–50 residues) insertion in the FMN-binding domain of cNOS, located -80 residues downstream from the CaM site, is the major sequence difference between iNOS and cNOS. This insertion is directly adjacent to the CaMbinding site on the three-dimensional structure. Several lines of evidence suggest that it functions as a control element.
Databáze: OpenAIRE