title: Metal transfer within the Escherichia coli HypB-HypA complex of hydrogenase accessory proteins.
abstract: The maturation of [NiFe]-hydrogenase in Escherichia coli is a complex process involving many steps and multiple accessory proteins. The two accessory proteins HypA and HypB interact with each other and are thought to cooperate to insert nickel into the active site of the hydrogenase-3 precursor protein. Both of these accessory proteins bind metal individually, but little is known about the metal-binding activities of the proteins once they assemble together into a functional complex. In this study, we investigate how complex formation modulates metal binding to the E. coli proteins HypA and HypB. This work lead to a re-evaluation of the HypA nickel affinity, revealing a KD on the order of 10(-8) M. HypA can efficiently remove nickel, but not zinc, from the metal-binding site in the GTPase domain of HypB, a process that is less efficient when complex formation between HypA and HypB is disrupted. Furthermore, nickel release from HypB to HypA is specifically accelerated when HypB is loaded with GDP, but not GTP. These results are consistent with the HypA-HypB complex serving as a transfer step in the relay of nickel from membrane transporter to its final destination in the hydrogenase active site and suggest that this complex contributes to the metal fidelity of this pathway.
authors.affiliation: Department of Chemistry, University of Toronto , 80 St. George St., Toronto, Ontario M5S 3H6, Canada.
authors.forename: Colin D
authors.initials: CD
authors.lastname: Douglas
authors.forename: Thanh T
authors.initials: TT
authors.lastname: Ngu
authors.forename: Harini
authors.initials: H
authors.lastname: Kaluarachchi
authors.forename: Deborah B
authors.initials: DB
authors.lastname: Zamble
mesh_terms: D001483:Base Sequence; D002352:Carrier Proteins / Q000378:metabolism*; D017931:DNA Primers; D004926:Escherichia coli / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000378:metabolism*; D006864:Hydrogenase / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins; D008670:Metals / Q000378:metabolism*; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D002352:Carrier Proteins; D017931:DNA Primers; D029968:Escherichia coli Proteins; C499625:HypA protein, E coli; C490324:HypB protein, E coli; D047908:Intracellular Signaling Peptides and Proteins; D008670:Metals; C043296:nickel-iron hydrogenase; D006864:Hydrogenase; D019204:GTP-Binding Proteins
references.citation: PLoS One. 2012;7(2):e32592
references.pmid: 22384275
references.citation: Adv Microb Physiol. 2006;51:1-71
references.pmid: 17091562
references.citation: J Biol Chem. 2012 Feb 24;287(9):6753-63
references.pmid: 22179820
references.citation: Science. 1988 Jun 3;240(4857):1302-9
references.pmid: 3287616
references.citation: Proc Natl Acad Sci U S A. 2003 Apr 1;100(7):3563-8
references.pmid: 12657732
references.citation: Mol Microbiol. 2011 Dec;82(5):1291-300
references.pmid: 22014167
references.citation: Arch Microbiol. 1992;158(6):444-51
references.pmid: 1482271
references.citation: J Bacteriol. 2002 Jul;184(14):3879-85
references.pmid: 12081959
references.citation: Biochem Soc Trans. 2005 Feb;33(Pt 1):83-5
references.pmid: 15667272
references.citation: J Inorg Biochem. 2012 Jun;111:173-81
references.pmid: 22459916
references.citation: Chem Biol. 2002 Jun;9(6):673-7
references.pmid: 12079778
references.citation: Nat Rev Microbiol. 2009 Jan;7(1):25-35
references.pmid: 19079350
references.citation: J Bacteriol. 2004 May;186(9):2603-11
references.pmid: 15090500
references.citation: J Biol Chem. 2007 Jun 1;282(22):16177-86
references.pmid: 17426034
references.citation: FEBS Lett. 2005 Aug 15;579(20):4292-6
references.pmid: 16061234
references.citation: Metallomics. 2013 Jun;5(7):804-7
references.pmid: 23708681
references.citation: Chem Rev. 2007 Oct;107(10):4206-72
references.pmid: 17927159
references.citation: J Bacteriol. 2005 Jul;187(14):4689-97
references.pmid: 15995183
references.citation: Appl Environ Microbiol. 2012 May;78(10):3614-21
references.pmid: 22344668
references.citation: J Bacteriol. 2003 Feb;185(3):726-34
references.pmid: 12533448
references.citation: Biochemistry. 2005 Sep 13;44(36):12229-38
references.pmid: 16142921
references.citation: Biometals. 2007 Jun;20(3-4):565-78
references.pmid: 17216401
references.citation: Met Ions Life Sci. 2013;12:375-416
references.pmid: 23595678
references.citation: Biochemistry. 2008 Nov 18;47(46):11981-91
references.pmid: 18942856
references.citation: Nat Protoc. 2007;2(6):1528-35
references.pmid: 17571060
references.citation: Biochemistry. 2011 Dec 20;50(50):10761-3
references.pmid: 22085337
references.citation: Nucleic Acids Res. 2003 Jul 1;31(13):3784-8
references.pmid: 12824418
references.citation: J Biol Chem. 2011 Dec 16;286(50):43081-90
references.pmid: 22016389
references.citation: J Bacteriol. 1985 Aug;163(2):454-9
references.pmid: 3894325
references.citation: J Bacteriol. 1956 Jan;71(1):70-80
references.pmid: 13286232
references.citation: Annu Rev Biochem. 2010;79:537-62
references.pmid: 20205585
references.citation: J Biol Inorg Chem. 2008 Nov;13(8):1205-18
references.pmid: 18604568
references.citation: Chem Rev. 2009 Oct;109(10):4644-81
references.pmid: 19788177
references.citation: FEBS Lett. 2011 Jan 21;585(2):291-4
references.pmid: 21185288
references.citation: Dalton Trans. 2012 Jul 14;41(26):7876-8
references.pmid: 22415482
references.citation: J Am Chem Soc. 2010 Aug 4;132(30):10338-51
references.pmid: 20662514
references.citation: Science. 2001 Jun 29;292(5526):2488-92
references.pmid: 11397910
references.citation: Curr Opin Chem Biol. 2007 Apr;11(2):159-65
references.pmid: 17275396
references.citation: J Biol Chem. 2000 Aug 18;275(33):25057-60
references.pmid: 10816601
references.citation: J Am Chem Soc. 2009 Jul 29;131(29):10031-40
references.pmid: 19621959
references.citation: Mol Microbiol. 2001 Jan;39(1):176-82
references.pmid: 11123699
references.citation: J Biol Chem. 2005 Feb 11;280(6):4360-6
references.pmid: 15569666
references.citation: Chem Rev. 2004 Feb;104(2):509-25
references.pmid: 14871133
references.citation: Nat Prod Rep. 2010 May;27(5):681-94
references.pmid: 20442959
references.citation: Anal Biochem. 1996 Jun 1;237(2):260-73
references.pmid: 8660575
references.citation: J Bacteriol. 2011 Mar;193(6):1359-68
references.pmid: 21239585
references.citation: J Biol Inorg Chem. 2011 Aug;16(6):857-68
references.pmid: 21544686
references.citation: Biometals. 2011 Oct;24(5):785-809
references.pmid: 21479832
references.citation: J Bacteriol. 1993 Feb;175(3):630-5
references.pmid: 8423137
references.citation: J Mol Biol. 2009 Dec 4;394(3):448-59
references.pmid: 19769985
references.citation: FEBS Lett. 2005 Aug 15;579(20):4287-91
references.pmid: 16051223
references.citation: J Bacteriol. 1995 Jul;177(14):4121-30
references.pmid: 7608087
references.citation: J Am Chem Soc. 2008 Oct 29;130(43):14056-7
references.pmid: 18834129