Researchers see activity of bacterial effector protein in molecular detail

Jun 11, 2012

Many plant and animal pathogens deploy effector proteins as part of their 'molecular arsenal' to facilitate infection and colonisation of their hosts. New research has revealed the structure of a bacterial effector molecule bound to its target protein in the host.

Gram-negative bacterial pathogens can deliver effector proteins through a specific secretion system, directly into host cells, to manipulate host for the benefit of the pathogen. The host cell processes targeted by effectors and the mechanisms used for manipulation are diverse. Knowledge of how effectors interface with host cell molecules is critical for understanding both mechanisms of pathogenesis and how effectors could be used to deliver new insights into biology.

Dr Mark Banfield at the John Innes Centre, funded by a grant from the Biotechnology and Biological Sciences Research Council (BBSRC), has uncovered the structure of a bacterial effector molecule called 'Cif' bound to its target (NEDD8) from the host. The Cif effector is found in a number of including strains of E. coli, Burkholderia, Photorhabdus and Yersinia species.

Delivery of Cif into host cells results in perturbation of the cell division cycle. One hypothesis suggests this could prevent rapid renewal of infected cells such as those in the lining of the gut, so helping bacterial colonisation. Researchers at the John Innes Centre also studied the of the effector protein in solution, and in collaboration with Drs. Taieb and Oswald, who are based in Toulouse, France, in model host cells.

Their work, publishing in the Online Early Edition this week, used protein structure determination to reveal the interface formed between the bacterial effector and the host target. The knowledge of this interface at the molecular level allowed small, directed changes to be made to the effector to determine the regions of the interface important for the interaction and the enzymatic activity in solution and in cells.

A thorough understanding of how this effector acts at the molecular level not only provides new information about the virulence mechanisms used by pathogens, it also suggests ways in which these effectors could be used as tools to probe functions related to the cell cycle, and how this relates to cellular biology.

Explore further: At dusk and dawn: Scientists pinpoint biological clock's synchronicity

More information: The molecular basis of NEDD8 deamidation by the bacterial effector protein Cif, Allister Crow, Richard K. Hughes, Frédéric Taieb, Eric Oswald & Mark J. Banfield, PNAS, 10.1073/pnas.1112107109

Related Stories

How plague-causing bacteria disarm host defense

May 24, 2007

Effector proteins are the bad guys that help bacterial pathogens do their job of infecting the host by crippling the body's immune system. In essence, they knock down the front door of resistance and disarm the cell's alarm ...

Structure of a virulent pathogen revealed

Dec 04, 2008

(PhysOrg.com) -- Like high-profile politicians, pathogenic bacteria dispatch advance teams to make way for their arrival. But these bacterial agents don’t just secure a safe passage, as a Secret Service ...

Potato blight plight looks promising for food security

Aug 10, 2009

Over 160 years since potato blight wreaked havoc in Ireland and other northern European countries, scientists funded by the Biotechnology and Biological Sciences Research Council (BBSRC) finally have the blight-causing pathogen ...

Revealing how a potato disease takes hold

Dec 22, 2011

Late blight is an economically devastating disease for potato farmers worldwide, causing tens of billions of dollars worth of damage each year. Phytophthora infestans, the causal agent of late blight, has ...

Recommended for you

Plants prepackage beneficial microbes in their seeds

Sep 29, 2014

Plants have a symbiotic relationship with certain bacteria. These 'commensal' bacteria help the pants extract nutrients and defend against invaders – an important step in preventing pathogens from contaminating fruits and ...

User comments : 0