title: Electronic and protein structural dynamics of a photosensory histidine kinase.
abstract: The bacterium Caulobacter crescentus encodes a two-component signaling protein, LovK, that contains an N-terminal photosensory LOV domain coupled to a C-terminal histidine kinase. LovK binds a flavin cofactor, undergoes a reversible photocycle, and displays regulated ATPase and autophosphorylation activity in response to visible light. Femtosecond to nanosecond visible absorption spectroscopy demonstrates congruence between full-length LovK and isolated LOV domains in the mechanism and kinetics of light-dependent cysteinyl-C4(a) adduct formation and rupture, while steady-state absorption and fluorescence line narrowing (FLN) spectroscopies reveal unique features in the electronic structure of the LovK flavin cofactor. In agreement with other sensor histidine kinases, ATP binds specifically to LovK with micromolar affinity. However, ATP binding to the histidine kinase domain of LovK has no apparent effect on global protein structure as assessed by differential Fourier transform infrared (FTIR) spectroscopy. Cysteinyl adduct formation results in only minor changes in the structure of LovK as determined by differential FTIR. This study provides insight into the structural underpinnings of LOV-mediated signal transduction in the context of a full-length histidine kinase. In particular, the data provide evidence for a model in which small changes in the tertiary/quaternary structure of LovK, as triggered by photon detection in the N-terminal LOV sensory domain, are sufficient to regulate histidine kinase activity.
authors.affiliation: Biophysics Group, Department of Physics and Astronomy, Faculty of Sciences, VU University, Amsterdam, The Netherlands.
authors.forename: Maxime T A
authors.initials: MT
authors.lastname: Alexandre
authors.forename: Erin B
authors.initials: EB
authors.lastname: Purcell
authors.forename: Rienk
authors.initials: R
authors.lastname: van Grondelle
authors.forename: Bruno
authors.initials: B
authors.lastname: Robert
authors.forename: John T M
authors.initials: JT
authors.lastname: Kennis
authors.forename: Sean
authors.initials: S
authors.lastname: Crosson
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D016935:Caulobacter crescentus / Q000201:enzymology*; D017124:Conserved Sequence; D004583:Electrons; D004789:Enzyme Activation; D005486:Flavin Mononucleotide / Q000737:chemistry / Q000378:metabolism; D000071677:Histidine Kinase; D008027:Light; D055537:Light Signal Transduction / Q000502:physiology*; D011485:Protein Binding; D011494:Protein Kinases / Q000737:chemistry* / Q000378:metabolism; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary
chemical_list: D001426:Bacterial Proteins; D005486:Flavin Mononucleotide; D011494:Protein Kinases; D000071677:Histidine Kinase
references.citation: Biophys J. 2008 Nov 15;95(10):4790-802
references.pmid: 18708458
references.citation: Biophys J. 2009 Feb 18;96(4):1462-70
references.pmid: 19217862
references.citation: Biochemistry. 2003 Jul 15;42(27):8183-91
references.pmid: 12846567
references.citation: Proc Natl Acad Sci U S A. 2006 Jul 18;103(29):10895-900
references.pmid: 16829579
references.citation: Phys Chem Chem Phys. 2008 Nov 28;10(44):6693-702
references.pmid: 18989482
references.citation: J Biol Chem. 2001 Sep 28;276(39):36493-500
references.pmid: 11443119
references.citation: Proc Natl Acad Sci U S A. 2007 Nov 13;104(46):18241-6
references.pmid: 17986614
references.citation: Biochemistry. 2007 Mar 20;46(11):3129-37
references.pmid: 17311415
references.citation: J Am Chem Soc. 1972 Mar 8;94(5):1730-40
references.pmid: 5015676
references.citation: Biochemistry. 2005 Mar 15;44(10):3653-62
references.pmid: 15751942
references.citation: Biophys J. 2002 May;82(5):2627-34
references.pmid: 11964249
references.citation: Biochemistry. 2005 May 24;44(20):7427-34
references.pmid: 15895986
references.citation: Biophys J. 2003 Feb;84(2 Pt 1):1192-201
references.pmid: 12547798
references.citation: Science. 2007 Aug 24;317(5841):1090-3
references.pmid: 17717187
references.citation: Nat Chem Biol. 2009 Nov;5(11):827-34
references.pmid: 19718042
references.citation: Nat Struct Biol. 2001 Apr;8(4):353-60
references.pmid: 11276258
references.citation: Photochem Photobiol Sci. 2008 Oct;7(10):1168-78
references.pmid: 18846280
references.citation: J Am Chem Soc. 2005 Feb 2;127(4):1088-9
references.pmid: 15669833
references.citation: Photosynth Res. 2009 Aug-Sep;101(2-3):105-18
references.pmid: 19578970
references.citation: J Phys Chem A. 2009 Aug 20;113(33):9365-75
references.pmid: 19639947
references.citation: Curr Opin Microbiol. 2008 Apr;11(2):168-78
references.pmid: 18400553
references.citation: Biochemistry. 2005 Dec 13;44(49):15978-85
references.pmid: 16331957
references.citation: Biochemistry. 2003 Apr 1;42(12):3385-92
references.pmid: 12653541
references.citation: Photochem Photobiol Sci. 2004 Jun;3(6):566-74
references.pmid: 15170486
references.citation: Biophys J. 2004 Feb;86(2):1051-60
references.pmid: 14747340
references.citation: Curr Opin Struct Biol. 2007 Oct;17(5):623-30
references.pmid: 17959372
references.citation: Proc Natl Acad Sci U S A. 1999 Jul 20;96(15):8779-83
references.pmid: 10411952
references.citation: Biochemistry. 2010 Feb 9;49(5):1024-32
references.pmid: 20052995
references.citation: Biochemistry. 1998 Sep 1;37(35):12269-79
references.pmid: 9724541
references.citation: Biochemistry. 2007 Jun 26;46(25):7405-15
references.pmid: 17542622
references.citation: Photochem Photobiol. 2007 Nov-Dec;83(6):1283-300
references.pmid: 18028200
references.citation: Photochem Photobiol Sci. 2010 Jan;9(1):47-56
references.pmid: 20062844
references.citation: J Phys Chem B. 2009 Nov 26;113(47):15610-8
references.pmid: 19891470
references.citation: Photochem Photobiol Sci. 2004 Jun;3(6):575-9
references.pmid: 15170487
references.citation: Biochemistry. 2000 Aug 8;39(31):9401-10
references.pmid: 10924135
references.citation: Eur Biophys J. 2007 Sep;36(7):831-9
references.pmid: 17443319
references.citation: Biochemistry. 2008 Jan 22;47(3):922-8
references.pmid: 18163650
references.citation: Biochemistry. 2009 Dec 8;48(48):11458-69
references.pmid: 19863128
references.citation: J Biol Chem. 1996 Jan 12;271(2):939-45
references.pmid: 8557708
references.citation: J Am Chem Soc. 2010 Apr 7;132(13):4935-45
references.pmid: 20222748
references.citation: J Phys Chem B. 2009 Jun 11;113(23):8192-8
references.pmid: 19449828
references.citation: Photochem Photobiol. 2002 May;75(5):479-87
references.pmid: 12017473
references.citation: Biophys J. 2008 Jul;95(1):312-21
references.pmid: 18339766
references.citation: Science. 1998 Nov 27;282(5394):1698-701
references.pmid: 9831559
references.citation: Biophys J. 2009 Jul 8;97(1):238-47
references.pmid: 19580761
references.citation: Biochemistry. 2004 Dec 28;43(51):16184-92
references.pmid: 15610012
references.citation: Biochemistry. 2002 Nov 26;41(47):13876-82
references.pmid: 12437344
references.citation: Biophys J. 2009 Jul 8;97(1):227-37
references.pmid: 19580760
references.citation: Biochemistry. 2004 Jul 6;43(26):8373-9
references.pmid: 15222749
references.citation: Biochemistry. 2003 Jan 14;42(1):2-10
references.pmid: 12515534