Structural highlights
Function
[HEMTB_METCA] Oxygen-binding protein. May be involved in a storage mechanism or for delivery to oxygen-requiring enzymes. The oxygen-binding site contains two iron atoms.[1]
Publication Abstract from PubMed
The bacteriohemerythrin (McHr) from Methylococcus capsulatus (Bath) is an oxygen carrier that serves as a transporter to deliver O2 from the cytosol of the bacterial cell body to the particulate methane monooxygenase residing in the intracytoplasmic membranes for methane oxidation. Here we report X-ray protein crystal structures of the recombinant wild type (WT) McHr and its L114A, L114Y and L114F mutants. The structure of the WT reveals a possible water tunnel in the McHr that might be linked to its faster autoxidation relative to hemerythrin in marine invertebrates. With Leu114 positioned at the end of this putative water tunnel, the hydrophobic side chain of this residue seems to play a prominent role in controlling the access of the water molecule required for autoxidation. This hypothesis is examined by comparing the autoxidation rates of the WT McHr with those of the L114A, L114Y and L114F mutants. The biochemical data are correlated with structural insights derived from the analysis of the putative water tunnels in the various McHr proteins provided by the X-ray structures.
The bacteriohemerythrin from Methylococcus capsulatus (Bath): Crystal structures reveal that Leu114 regulates a water tunnel.,Chen KH, Chuankhayan P, Wu HH, Chen CJ, Fukuda M, Yu SS, Chan SI J Inorg Biochem. 2015 Apr 10. pii: S0162-0134(15)00094-X. doi:, 10.1016/j.jinorgbio.2015.04.001. PMID:25890483[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Karlsen OA, Ramsevik L, Bruseth LJ, Larsen O, Brenner A, Berven FS, Jensen HB, Lillehaug JR. Characterization of a prokaryotic haemerythrin from the methanotrophic bacterium Methylococcus capsulatus (Bath). FEBS J. 2005 May;272(10):2428-40. PMID:15885093 doi:http://dx.doi.org/10.1111/j.1742-4658.2005.04663.x
- ↑ Chen KH, Chuankhayan P, Wu HH, Chen CJ, Fukuda M, Yu SS, Chan SI. The bacteriohemerythrin from Methylococcus capsulatus (Bath): Crystal structures reveal that Leu114 regulates a water tunnel. J Inorg Biochem. 2015 Apr 10. pii: S0162-0134(15)00094-X. doi:, 10.1016/j.jinorgbio.2015.04.001. PMID:25890483 doi:http://dx.doi.org/10.1016/j.jinorgbio.2015.04.001
