Effector proteins from P450(cam) and methane monooxygenase: lessons in tuning nature's powerful reagents.
Effector proteins alter the kinetic or catalytic course of many oxygenase reactions. One of the first oxygenase effectors to be described was putidaredoxin, which serves to gate electron transfer into oxy-P450(cam). In the nonheme, methane monooxygenase (MMO) system, the B-component (MMOB) serves a distinct effector function by gating substrate and oxygen into the active site of the hydroxylase component (MMOH). Here the binding parameters and binding surfaces of the MMOB-MMOH complex are determined by site-specific labeling, fluorescence titrations, chemical cross-linking, and MALDI-TOF peptide identification. Based on these data, a model for the bimolecular complex is described and a hypothesis for the structural basis for the effector function is elaborated. The bearing on the putidaredoxin effector function is discussed.
Brazeau
Brian J
BJ
Department of Biochemistry, Molecular Biology, and Biophysics, and the Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, MN 55455, USA.
Wallar
Bradley J
BJ
Lipscomb
John D
JD
D001665:Binding Sites; D019475:Camphor 5-Monooxygenase / Q000737:chemistry*; D003067:Coenzymes / Q000737:chemistry*; D003198:Computer Simulation; D003432:Cross-Linking Reagents / Q000737:chemistry; D044927:Electron-Transferring Flavoproteins; D004789:Enzyme Activation; D004795:Enzyme Stability; D008958:Models, Molecular; D009154:Mutation; D010105:Oxygenases / Q000737:chemistry*; D011485:Protein Binding; D013329:Structure-Activity Relationship
D003067:Coenzymes; D003432:Cross-Linking Reagents; D044927:Electron-Transferring Flavoproteins; D010105:Oxygenases; C021555:methane monooxygenase; D019475:Camphor 5-Monooxygenase