Deciphering Bacterial Flagellar Gene Regulatory Networks in the Genomic Era

By jpeza - Posted on 31 Julio 2009

Fecha Publicación: 
1 Ene 2009
Datos del paper
Autor Principal: 
Todd G. Smith
Página Inicial: 
Página Final: 

Synthesis of the bacterialflagellumisacomplexprocessinvolving

dozens of structural and regulatory genes.Assembly of the flagellum

is a highly-ordered process, and in most flagellated bacteria

the structural genes are expressed in a transcriptional hierarchy

that results in the products of these genes being made as they are

needed for assembly.Temporal regulation of the flagellar genes is

achieved through sophisticated regulatory networks that utilize

checkpoints in the flagellar assembly pathway to coordinate

expression of flagellar genes. Traditionally,flagellar transcriptional

hierarchies are divided into various classes. Class Igenes, whichare

the first genes expressed, encode a master regulator that initiates

the transcriptional hierarchy. The master regulator activates transcription

a set of structural and regulatory genes referred to as

class 11genes, which in turn affect expression of subsequent classes

of flagellar genes. We review here the literature on the expression

and activity of several known master regu!ators, including FlhDC,

CtrA, VisNR,FleQ, FlrA, FlaK,LafK,SwrA, and MogR. We also

examine the Department of EnergyJoint Genomes Institute database

to make predictions about the distribution of these regulators.

Manybacteria employ the alternative sigmafactors cr54and/or cr28

to regulate transcription of later classes of flagellar genes. Transcription

by cr54_RNApolymerase holoenzyme requires an activator,

and we review the literature on the cr54-dependent activators

that control flagellar gene expression in severa! bacterial systems,

as well as make predictions about other systems that may utilize

cr54for flagellar gene regulation. Finally,we review the prominent

systems that utilize cr28and its antagonist, the anti-cr28factor FlgM,

along with some systems that utilize alternative mechanisms for

regulating flagellar gene expression.

Dirección del Autor: 

Department of Mierobiology, University of Georgia, Athens, Georgia, USA

1 Corresponding author: 527 Biologieal Seienee Building, University of Georgia, Athens, Georgia 30602

Synthesis of the bacterial ; bacterial flagellum ; regulatory genes

Timothy R. Hoover

[file] advances_in_applied_microbiology_2009_vol 67_pp 257-295.pdf7.53 MB
[file] advances in applied microbiology 2009 67 257-295 (2).pdf5.74 MB
[file] advances in applied microbiology 2009 67 257-295 (3).pdf4.39 MB