3CHX

Crystal structure of Methylosinus trichosporium OB3b particulate methane monooxygenase (pMMO)

Summary for 3CHX

• Entry DOI: 10.2210/pdb3chx/pdb
• Descriptor: PmoB, PmoA, PmoC, ... (6 entities in total)
• Functional Keywords: membrane protein, methane, beta barrel
• Biological source: Methylosinus trichosporium; More
• Total number of polymer chains: 15
• Total formula weight: 314615.14

Authors

Hakemian, A.S. (deposition date: 2008-03-10, release date: 2008-07-15, Last modification date: 2023-08-30)

Primary citation

Hakemian, A.S.,Kondapalli, K.C.,Telser, J.,Hoffman, B.M.,Stemmler, T.L.,Rosenzweig, A.C.
The metal centers of particulate methane monooxygenase from Methylosinus trichosporium OB3b.
Biochemistry, 47:6793-6801, 2008

PubMed Abstract: Particulate methane monooxygenase (pMMO) is a membrane-bound metalloenzyme that oxidizes methane to methanol in methanotrophic bacteria. The nature of the pMMO active site and the overall metal content are controversial, with spectroscopic and crystallographic data suggesting the presence of a mononuclear copper center, a dinuclear copper center, a trinuclear center, and a diiron center or combinations thereof. Most studies have focused on pMMO from Methylococcus capsulatus (Bath). pMMO from a second organism, Methylosinus trichosporium OB3b, has been purified and characterized by spectroscopic and crystallographic methods. Purified M. trichosporium OB3b pMMO contains approximately 2 copper ions per 100 kDa protomer. Electron paramagnetic resonance (EPR) spectroscopic parameters indicate that type 2 Cu(II) is present as two distinct species. Extended X-ray absorption fine structure (EXAFS) data are best fit with oxygen/nitrogen ligands and reveal a Cu-Cu interaction at 2.52 A. Correspondingly, X-ray crystallography of M. trichosporium OB3b pMMO shows a dinuclear copper center, similar to that observed previously in the crystal structure of M. capsulatus (Bath) pMMO. There are, however, significant differences between the pMMO structures from the two organisms. A mononuclear copper center present in M. capsulatus (Bath) pMMO is absent in M. trichosporium OB3b pMMO, whereas a metal center occupied by zinc in the M. capsulatus (Bath) pMMO structure is occupied by copper in M. trichosporium OB3b pMMO. These findings extend previous work on pMMO from M. capsulatus (Bath) and provide new insight into the functional importance of the different metal centers.

PubMed: 18540635
DOI: 10.1021/bi800598h

Experimental method

X-RAY DIFFRACTION (3.9 Å)