Send to:

Choose Destination
See comment in PubMed Commons below
FEBS Open Bio. 2012 Jul 27;2:173-7. doi: 10.1016/j.fob.2012.07.008. Print 2012.

Exploring potassium-dependent GTP hydrolysis in TEES family GTPases.

Author information

  • 1Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India.


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.


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

Free PMC Article
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science Icon for PubMed Central
    Loading ...
    Write to the Help Desk