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.
|Original language||English (US)|
|Number of pages||6|
|Journal||Biochemical and Biophysical Research Communications|
|State||Published - Dec 5 2003|
Bibliographical noteFunding Information:
This work was supported by National Institutes of Health Grant GM40466. We thank Dr. LeeAnn Higgins and Thomas P. Krick for assistance in collecting and interpreting the mass spectrometry data and Dr. David D. Thomas for the use of the ISS K2 Fluorometer.
- Component docking
- Methane monooxygenase