Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
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Target Concepts:
Gene/Protein
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Query: EC:3.6.3.1 (
Mg2+-ATPase
)
1,484
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The Y. enterocolitica O:8(YeO8) O-antigen repeat units consist of five sugar residues: N-acetyl-D-galactosamine (GalNAc), D-galactose (Gal), D-mannose (Man), L-fucose (Fuc), and 6-deoxy-D-gulose (6d-Gul). The nucleotide sequence of the O-antigen gene cluster of the YeO8 strain 8081-c was determined. Altogether, 18 open reading frames (ORFs) were identified and shown to be essential for O-antigen biosynthesis. We previously characterized the 3'-end of the O-antigen gene cluster and identified four genes: two for GDP-Man biosynthesis, one for
UDP-Gal
biosynthesis, and one for O-antigen polymerase. Based on sequence similarity, Tn5-insertion phenotypes and chemical analysis, the 14 new genes were assigned the following functions: four genes are involved in the biosynthesis of CDP-6d-Gul and two in GDP-Fuc biosynthesis. Five gene products were assigned sugar transferase functions and one gene product was similar to Wzx, the O-antigen
flippase
. Two genes remained unassigned. By genetic complementation we also showed that YeO8 O-antigen biosynthesis was dependent on N-acetyl-glucosaminyl:undecaprenylphosphate transferase (GlcNAc transferase), the WecA (formerly known as Rfe) protein. Data obtained from chemical-composition analysis suggest that in addition to being GlcNAc transferase, WecA may also function as a GalNAc transferase. Using a restriction-deficient derivative of Y. enterocolitica O:8 strain 8081, a rough mutant, designated 8081-R2, was isolated. 8081-R2 was complemented in trans with a cloned O-antigen gene cluster restoring surface O-antigen expression. The virulence of the wild-type strain and that of the complemented strain were significantly higher (approx. 100-fold) than that of the rough mutant in an orally infected mouse model, showing that YeO8 O-antigen is a virulence factor.
...
PMID:Molecular and chemical characterization of the lipopolysaccharide O-antigen and its role in the virulence of Yersinia enterocolitica serotype O:8. 900 21
The cell wall polymers wall teichoic acid (WTA) and lipoteichoic acid (LTA) are often modified with glycosyl and D-alanine residues. Recent studies have shown that a three-component glycosylation system is used for the modification of LTA in several Gram-positive bacteria including
Bacillus subtilis
and
Listeria monocytogenes
. In the
L. monocytogenes
1/2a strain 10403S, the cytoplasmic glycosyltransferase GtlA is thought to use
UDP-galactose
to produce the C
55
-P-galactose lipid intermediate, which is transported across the membrane by an unknown
flippase
. Next, the galactose residue is transferred onto the LTA backbone on the outside of the cell by the glycosyltransferase GtlB. Here we show that GtcA is necessary for the glycosylation of LTA in
L. monocytogenes
10403S and
B. subtilis
168 and we hypothesize that these proteins act as C
55
-P-sugar flippases. With this we revealed that GtcA is involved in the glycosylation of both teichoic acid polymers in
L. monocytogenes
10403S, namely WTA with N-acetylglucosamine and LTA with galactose residues. These findings indicate that the
L. monocytogenes
GtcA protein can act on different C
55
-P-sugar intermediates. Further characterization of GtcA in
L. monocytogenes
led to the identification of residues essential for its overall function as well as residues, which predominately impact WTA or LTA glycosylation.
...
PMID:GtcA is required for LTA glycosylation in
Listeria monocytogenes
serovar 1/2a and
Bacillus subtilis
. 3274 50
