| Structural highlights
Function
[MBCTN_METTR] Chalkophore involved in scavenging, uptake and suppression of toxicity of copper. Each apo-methanobactin (apo-mb) complexes 1 Cu(2+) or Cu(1+) ion to form Cu(1+)-mb (Cu-mb) which is then taken up by the cell. Enhances growth rate in the presence of copper and reduces growth lag upon exposition to elevated levels of copper. Cu-mb contributes to the switchover from soluble methane monooxygenase (sMMO) to the membrane-bound particulate MMO (pMMO) by inducing transcription of pMMO subunit A. It also stimulates the enzymatic activity of pMMO. In the absence of copper, binds other metal ions, like Zn(2+), Ag(1+), Au(3+), Co(2+), Cd(2+), Fe(3+), Hg(2+), Mn(2+), Ni(2+), Pb(2+) or U(6+), but not Ba(2+), Ca(2+), La(2+), Mg(2+) or Sr(2+). Uptake is an active process, which may involve TonB-dependent transporters, and as such does not involve porins. Cu-Mb can be taken up by other methanotrophic bacteria but not by E.coli. Has Cu-dependent superoxide dismutase-like activity. Shows reductant-dependent oxidase and hydrogen peroxide reductase activities. Reduces copper-levels in liver in a rat model of Wilson disease.[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13]
Publication Abstract from PubMed
Methanobactins (mbs) are a class of copper-binding peptides produced by aerobic methane oxidizing bacteria (methanotrophs) that have been linked to the substantial copper needs of these environmentally important microorganisms. The only characterized mbs are those from Methylosinus trichosporium OB3b and Methylocystis strain SB2. M. trichosporium OB3b produces a second mb (mb-Met), which is missing the C-terminal Met residue from the full-length form (FL-mb). The as-isolated copper-loaded mbs bind Cu(I). The absence of the Met has little influence on the structure of the Cu(I) site, and both molecules mediate switchover from the soluble iron methane mono-oxygenase to the particulate copper-containing enzyme in M. trichosporium OB3b cells. Cu(II) is reduced in the presence of the mbs under our experimental conditions, and the disulfide plays no role in this process. The Cu(I) affinities of these molecules are extremely high with values of (6-7) x 10(20) M(-1) determined at pH >/= 8.0. The affinity for Cu(I) is 1 order of magnitude lower at pH 6.0. The reduction potentials of copper-loaded FL-mb and mb-Met are 640 and 590 mV respectively, highlighting the strong preference for Cu(I) and indicating different Cu(II) affinities for the two forms. Cleavage of the disulfide bridge results in a decrease in the Cu(I) affinity to approximately 9 x 10(18) M(-1) at pH 7.5. The two thiolates can also bind Cu(I), albeit with much lower affinity ( approximately 3 x 10(15) M(-1) at pH 7.5). The high affinity of mbs for Cu(I) is consistent with a physiological role in copper uptake and protection.
Copper-Binding Properties and Structures of Methanobactins from Methylosinus trichosporium OB3b.,El Ghazouani A, Basle A, Firbank SJ, Knapp CW, Gray J, Graham DW, Dennison C Inorg Chem. 2011 Jan 21. PMID:21254756[14]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Kim HJ, Graham DW, DiSpirito AA, Alterman MA, Galeva N, Larive CK, Asunskis D, Sherwood PM. Methanobactin, a copper-acquisition compound from methane-oxidizing bacteria. Science. 2004 Sep 10;305(5690):1612-5. PMID:15361623 doi:10.1126/science.1098322
- ↑ Kim HJ, Galeva N, Larive CK, Alterman M, Graham DW. Purification and physical-chemical properties of methanobactin: a chalkophore from Methylosinus trichosporium OB3b. Biochemistry. 2005 Apr 5;44(13):5140-8. PMID:15794651 doi:10.1021/bi047367r
- ↑ Hakemian AS, Tinberg CE, Kondapalli KC, Telser J, Hoffman BM, Stemmler TL, Rosenzweig AC. The copper chelator methanobactin from Methylosinus trichosporium OB3b binds copper(I). J Am Chem Soc. 2005 Dec 14;127(49):17142-3. PMID:16332035 doi:10.1021/ja0558140
- ↑ Choi DW, Antholine WE, Do YS, Semrau JD, Kisting CJ, Kunz RC, Campbell D, Rao V, Hartsel SC, DiSpirito AA. Effect of methanobactin on the activity and electron paramagnetic resonance spectra of the membrane-associated methane monooxygenase in Methylococcus capsulatus Bath. Microbiology. 2005 Oct;151(Pt 10):3417-26. PMID:16207923 doi:10.1099/mic.0.28169-0
- ↑ Choi DW, Zea CJ, Do YS, Semrau JD, Antholine WE, Hargrove MS, Pohl NL, Boyd ES, Geesey GG, Hartsel SC, Shafe PH, McEllistrem MT, Kisting CJ, Campbell D, Rao V, de la Mora AM, Dispirito AA. Spectral, kinetic, and thermodynamic properties of Cu(I) and Cu(II) binding by methanobactin from Methylosinus trichosporium OB3b. Biochemistry. 2006 Feb 7;45(5):1442-53. PMID:16445286 doi:10.1021/bi051815t
- ↑ Choi DW, Do YS, Zea CJ, McEllistrem MT, Lee SW, Semrau JD, Pohl NL, Kisting CJ, Scardino LL, Hartsel SC, Boyd ES, Geesey GG, Riedel TP, Shafe PH, Kranski KA, Tritsch JR, Antholine WE, DiSpirito AA. Spectral and thermodynamic properties of Ag(I), Au(III), Cd(II), Co(II), Fe(III), Hg(II), Mn(II), Ni(II), Pb(II), U(IV), and Zn(II) binding by methanobactin from Methylosinus trichosporium OB3b. J Inorg Biochem. 2006 Dec;100(12):2150-61. Epub 2006 Sep 20. PMID:17070918 doi:10.1016/j.jinorgbio.2006.08.017
- ↑ Knapp CW, Fowle DA, Kulczycki E, Roberts JA, Graham DW. Methane monooxygenase gene expression mediated by methanobactin in the presence of mineral copper sources. Proc Natl Acad Sci U S A. 2007 Jul 17;104(29):12040-5. Epub 2007 Jul 5. PMID:17615240 doi:10.1073/pnas.0702879104
- ↑ Choi DW, Semrau JD, Antholine WE, Hartsel SC, Anderson RC, Carey JN, Dreis AM, Kenseth EM, Renstrom JM, Scardino LL, Van Gorden GS, Volkert AA, Wingad AD, Yanzer PJ, McEllistrem MT, de la Mora AM, DiSpirito AA. Oxidase, superoxide dismutase, and hydrogen peroxide reductase activities of methanobactin from types I and II methanotrophs. J Inorg Biochem. 2008 Aug;102(8):1571-80. doi: 10.1016/j.jinorgbio.2008.02.003., Epub 2008 Feb 20. PMID:18372044 doi:10.1016/j.jinorgbio.2008.02.003
- ↑ Krentz BD, Mulheron HJ, Semrau JD, Dispirito AA, Bandow NL, Haft DH, Vuilleumier S, Murrell JC, McEllistrem MT, Hartsel SC, Gallagher WH. 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. 2010 Nov 30;49(47):10117-30. doi: 10.1021/bi1014375. Epub 2010 Nov , 4. PMID:20961038 doi:10.1021/bi1014375
- ↑ Choi DW, Bandow NL, McEllistrem MT, Semrau JD, Antholine WE, Hartsel SC, Gallagher W, Zea CJ, Pohl NL, Zahn JA, DiSpirito AA. Spectral and thermodynamic properties of methanobactin from gamma-proteobacterial methane oxidizing bacteria: a case for copper competition on a molecular level. J Inorg Biochem. 2010 Dec;104(12):1240-7. doi: 10.1016/j.jinorgbio.2010.08.002., Epub 2010 Aug 14. PMID:20817303 doi:10.1016/j.jinorgbio.2010.08.002
- ↑ El Ghazouani A, Basle A, Firbank SJ, Knapp CW, Gray J, Graham DW, Dennison C. Copper-Binding Properties and Structures of Methanobactins from Methylosinus trichosporium OB3b. Inorg Chem. 2011 Jan 21. PMID:21254756 doi:10.1021/ic101965j
- ↑ Balasubramanian R, Kenney GE, Rosenzweig AC. Dual pathways for copper uptake by methanotrophic bacteria. J Biol Chem. 2011 Oct 28;286(43):37313-9. doi: 10.1074/jbc.M111.284984. Epub 2011, Sep 7. PMID:21900235 doi:10.1074/jbc.M111.284984
- ↑ Summer KH, Lichtmannegger J, Bandow N, Choi DW, DiSpirito AA, Michalke B. The biogenic methanobactin is an effective chelator for copper in a rat model for Wilson disease. J Trace Elem Med Biol. 2011 Jan;25(1):36-41. doi: 10.1016/j.jtemb.2010.12.002., Epub 2011 Jan 15. PMID:21242075 doi:10.1016/j.jtemb.2010.12.002
- ↑ El Ghazouani A, Basle A, Firbank SJ, Knapp CW, Gray J, Graham DW, Dennison C. Copper-Binding Properties and Structures of Methanobactins from Methylosinus trichosporium OB3b. Inorg Chem. 2011 Jan 21. PMID:21254756 doi:10.1021/ic101965j
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