title: Exploring potassium-dependent GTP hydrolysis in TEES family GTPases.
abstract: GTPases are important regulatory proteins that hydrolyze GTP to GDP. A novel GTP-hydrolysis mechanism is employed by MnmE, YqeH and FeoB, where a potassium ion plays a role analogous to the Arginine finger of the Ras-RasGAP system, to accelerate otherwise slow GTP hydrolysis rates. In these proteins, two conserved asparagines and a 'K-loop' present in switch-I, were suggested as attributes of GTPases employing a K(+)-mediated mechanism. Based on their conservation, a similar mechanism was suggested for TEES family GTPases. Recently, in Dynamin, Fzo1 and RbgA, which also conserve these attributes, a similar mechanism was shown to be operative. Here, we probe K(+)-activated GTP hydrolysis in TEES (TrmE-Era-EngA-YihA-Septin) GTPases - Era, EngB and the two contiguous G-domains, GD1 and GD2 of YphC (EngA homologue) - and also in HflX, another GTPase that also conserves the same attributes. While GD1-YphC and Era exhibit a K(+)-mediated activation of GTP hydrolysis, surprisingly GD2-YphC, EngB and HflX do not. Therefore, the attributes identified thus far, do not necessarily predict a K(+)-mechanism in GTPases and hence warrant extensive structural investigations.
authors: Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India.
authors: Abu
authors: A
authors: Rafay
authors: Soneya
authors: S
authors: Majumdar
authors: Balaji
authors: B
authors: Prakash
keywords: EngA, Essential Neisseria gonorrhoeae GTPase; Era, E. coli ras; GTPases; HAS-GTPases; HAS-GTPases, Hydrophobic Amino acid Substituted for catalytic glutamine-GTPases; Hydrolysis mechanism; K+ stimulated hydrolysis; K-loop; TEES, TrmE-Era-EngA-YihA-Septin
references: Annu Rev Biochem. 2011;80:943-71
references: 21675921
references: J Mol Biol. 2002 Mar 15;317(1):41-72
references: 11916378
references: Nature. 1991 Jan 10;349(6305):117-27
references: 1898771
references: J Cell Sci. 2011 Apr 1;124(Pt 7):1126-35
references: 21385840
references: J Biol Chem. 2010 May 7;285(19):14594-602
references: 20220129
references: PLoS One. 2010 Apr 01;5(4):e9944
references: 20376346
references: EMBO J. 2006 Jun 21;25(12):2940-51
references: 16763562
references: Nucleic Acids Res. 2009 Apr;37(7):2359-70
references: 19246542
references: J Mol Biol. 2003 Apr 4;327(4):843-55
references: 12654267
references: Biochem Biophys Res Commun. 2009 Feb 6;379(2):201-5
references: 19109926
references: Proc Natl Acad Sci U S A. 2006 Aug 15;103(33):12359-64
references: 16894162
references: Nature. 2010 May 27;465(7297):435-40
references: 20428113
references: Nature. 1990 Nov 8;348(6297):125-32
references: 2122258
references: Proteins. 2005 May 1;59(2):332-8
references: 15726588
references: Biochem Biophys Res Commun. 2011 May 13;408(3):459-64
references: 21527254
references: Science. 1996 Jul 5;273(5271):115-7
references: 8658179
references: PLoS One. 2012;7(1):e30547
references: 22276211
references: Trends Biochem Sci. 1998 Jul;23(7):257-62
references: 9697416
references: J Biol Chem. 1995 Feb 3;270(5):2251-7
references: 7836458
references: Structure. 2002 Dec;10(12):1649-58
references: 12467572
references: Nat Rev Mol Cell Biol. 2009 Jun;10(6):423-9
references: 19424291
references: J Biol Chem. 2012 Mar 9;287(11):8417-23
references: 22267738