Format

Send to

Choose Destination
J Bacteriol. 2006 Feb;188(3):882-93.

Functional and topological characterization of novel components of the comB DNA transformation competence system in Helicobacter pylori.

Author information

1
Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Ludwig-Maximilians-Universität, Pettenkoferstr. 9a, D-80336 München, Germany.

Abstract

Helicobacter pylori is one of the most diverse bacterial species known. A rational basis for this genetic variation may be provided by its natural competence for genetic transformation and high-frequency recombination. Many bacterial competence systems have homology with proteins that are involved in the assembly of type IV pili and type II secretion systems. In H. pylori, DNA uptake relies on a transport system related to type IV secretion systems (T4SS) designated the comB system. The prototype of a T4SS in Agrobacterium tumefaciens consists of 11 VirB proteins and VirD4, which form the core unit necessary for the delivery of single proteins or large nucleoprotein complexes into target cells. In the past we identified proteins ComB4 and ComB7 through ComB10 as being involved in the process of DNA uptake in H. pylori. In this study we identified and functionally characterized further (T4SS-homologous) components of the comB transformation competence system. By combining computer prediction modeling, experimental topology determination, generation of knockout strains, and genetic complementation studies we identified ComB2, ComB3, and ComB6 as essential components of the transformation apparatus, structurally and functionally homologous to VirB2, VirB3, and VirB6, respectively. comB2, comB3, and comB4 are organized as a separate operon. Thus, for the H. pylori comB system, all T4SS core components have been identified except for homologues to VirB1, VirD4, VirB5, and VirB11.

PMID:
16428391
PMCID:
PMC1347336
DOI:
10.1128/JB.188.3.882-893.2006
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center