A comparison of methanobactins from Methylosinus trichosporium OB3b and Methylocystis strain SB2 predicts methanobactins are synthesized from diverse peptide precursors modified to create a common core for binding and reducing copper ions

Krentz, Benjamin D., Mulheron, Heidi J., Semrau, Jeremy D., DiSpirito, Alan A., Bandow, Nathan L., Haft, Daniel H., Vuilleumier, Stéphane, Murrell, J. Colin, McEllistrem, Marcus T., Hartsel, Scott C. and Gallagher, Warren H. (2010) A comparison of methanobactins from Methylosinus trichosporium OB3b and Methylocystis strain SB2 predicts methanobactins are synthesized from diverse peptide precursors modified to create a common core for binding and reducing copper ions. Biochemistry, 49 (47). pp. 10117-10130. ISSN 0006-2960

Full text not available from this repository. (Request a copy)

Abstract

Methanobactins (mb) are low-molecular mass, copper-binding molecules secreted by most methanotrophic bacteria. These molecules have been identified for a number of methanotrophs, but only the one produced by Methylosinus trichosporium OB3b (mb-OB3b) has to date been chemically characterized. Here we report the chemical characterization and copper binding properties of a second methanobactin, which is produced by Methylocystis strain SB2 (mb-SB2). mb-SB2 shows some significant similarities to mb-OB3b, including its spectral and metal binding properties, and its ability to bind and reduce Cu(II) to Cu(I). Like mb-OB3b, mb-SB2 contains two five-member heterocyclic rings with associated enethiol groups, which together form the copper ion binding site. mb-SB2 also displays some significant differences compared to mb-OB3b, including the number and types of amino acids used to complete the structure of the molecule, the presence of an imidazolone ring in place of one of the oxazolone rings found in mb-OB3b, and the presence of a sulfate group not found in mb-OB3b. The sulfate is bonded to a threonine-like side chain that is associated with one of the heterocyclic rings and may represent the first example of this type of sulfate group found in a bacterially derived peptide. Acid-catalyzed hydrolysis and decarboxylation of the oxazolone rings found in mb-OB3b and mb-SB2 produce pairs of amino acid residues and suggest that both mb-OB3b and mb-SB2 are derived from peptides. In support of this, the gene for a ribosomally produced peptide precursor for mb-OB3b has been identified in the genome of M. trichosporium OB3b. The gene sequence indicates that the oxazolone rings in mb-OB3b are derived from the combination of a cysteine residue and the carbonyl from the preceding residue in the peptide sequence. Taken together, the results suggest methanobactins make up a structurally diverse group of ribosomally produced, peptide-derived molecules, which share a common pair of five-member rings with associated enethiol groups that are able to bind, reduce, and stabilize copper ions in an aqueous environment.

Item Type:	Article
Faculty \ School:	Faculty of Science > School of Environmental Sciences
UEA Research Groups:	Faculty of Science > Research Groups > Environmental Biology Faculty of Science > Research Centres > Centre for Ecology, Evolution and Conservation Faculty of Science > Research Groups > Resources, Sustainability and Governance (former - to 2018) Faculty of Science > Research Groups > Marine and Atmospheric Sciences (former - to 2017)
Depositing User:	Rhiannon Harvey
Date Deposited:	27 Mar 2012 09:55
Last Modified:	23 Oct 2022 01:09
URI:	https://ueaeprints.uea.ac.uk/id/eprint/38484
DOI:	10.1021/bi1014375

Actions (login required)

View Item