Biology Reference
In-Depth Information
Abstract
Campylobacter jejuni is a zoonotic Gram-negative bacterial pathogen that is exposed to
reactive nitrogen species, such as nitric oxide, from a variety of sources. To combat the
toxic effects of this nitrosative stress, C. jejuni upregulates a small regulon under the con-
trol of the transcriptional activator NssR, which positively regulates the expression of a
single-domain globin protein (Cgb) and a truncated globin protein (Ctb). Cgb has pre-
viously been shown to detoxify nitric oxide, but the role of Ctb remains contentious. As
C. jejuni is amenable to genetic manipulation, and its globin proteins are easily
expressed and purified, a combination of mutagenesis, complementation, trans-
criptomics, spectroscopic characterisation and structural analyses has been used to
probe the regulation, function and structure of Cgb and Ctb. This ability to study
Cgb and Ctb with such a multi-pronged approach is a valuable asset, especially since
only a small fraction of known globin proteins have been functionally characterised.
ABBREVIATIONS
CcP cytochrome
c
peroxidase
Cgb
Campylobacter
single-domain haemoglobin
CioAB
Campylobacter
cyanide-insensitive oxidase
Ctb
Campylobacter
-truncated haemoglobin
DMSO dimethyl sulphoxide
FHb flavohaemoglobin
GSNO
S
-nitrosoglutathione
HbN
M. tuberculosis
TrHbI
HbO
M. tuberculosis
TrHbII
Hmp
E. coli
flavohaemoglobin
Mb myoglobin
MFS Miller Fisher syndrome
Nap nitrate reductase
NOC-5 3-(aminopropyl)-1-hydroxy-3-isopropyl-2-oxo-1-triazene
NOC-7 3-(2-hydroxy-1-methyl-2-nitrosohydrazino)-
N
-methyl-1-propanamine
NOC-18 (
Z
)-1-[2-(2-aminoethyl)-
N
-(2-ammonioethyl)amino]diazen-1-ium-1,2-diolate
NOD nitric oxide dioxygenase
NOS NO synthase
NssR
Campylobacter
nitrosative stress-sensing regulator
RNS reactive nitrogen species
ROS reactive oxygen species
SDHb single-domain haemoglobin
SNAP
S
-nitroso-
N
-acetylpenicillamine
SNOs
S
-nitrosothiols
SNP sodium nitroprusside
swMb sperm whale myoglobin
T family truncated Mb-fold family
TMAO trimethylamine-
N
-oxide
TrHb truncated haemoglobin
Vgb
Vitreoscilla
single-domain haemoglobin
