Molecular analysis of three Aeromonas hydrophila AH-3 (serotype O34) lipopolysaccharide core biosynthesis gene clusters.
By the isolation of three different Aeromonas hydrophila strain AH-3 (serotype O34) mutants with an altered lipopolysaccharide (LPS) migration in gels, three genomic regions encompassing LPS core biosynthesis genes were identified and characterized. When possible, mutants were constructed using each gene from the three regions, containing seven, four, and two genes (regions 1 to 3, respectively). The mutant LPS core structures were elucidated by using mass spectrometry, methylation analysis, and comparison with the full core structure of an O-antigen-lacking AH-3 mutant previously established by us. Combining the gene sequence and complementation test data with the structural data and phenotypic characterization of the mutant LPSs enabled a presumptive assignment of all LPS core biosynthesis gene functions in A. hydrophila AH-3. The three regions and the genes contained are in complete agreement with the recently sequenced genome of A. hydrophila ATCC 7966. The functions of the A. hydrophila genes waaC in region 3 and waaF in region 2 were completely established, allowing the genome annotations of the two heptosyl transferase products not previously assigned. Having the functions of all genes involved with the LPS core biosynthesis and most corresponding single-gene mutants now allows experimental work on the role of the LPS core in the virulence of A. hydrophila.
Jimenez
Natalia
N
Departamento Microbiología, Facultad Biología, Universidad Barcelona, Diagonal 645, 08071 Barcelona, Spain.
Canals
Rocío
R
Lacasta
Anna
A
Kondakova
Anna N
AN
Lindner
Buko
B
Knirel
Yuriy A
YA
Merino
Susana
S
Regué
Miguel
M
Tomás
Juan M
JM
D016980:Aeromonas hydrophila / Q000235:genetics* / Q000378:metabolism; D002240:Carbohydrate Sequence; D003001:Cloning, Molecular; D023061:Gene Order; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D016695:Glycosyltransferases / Q000235:genetics; D008969:Molecular Sequence Data; D015394:Molecular Structure; D005810:Multigene Family; D009154:Mutation; D019081:O Antigens / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D017422:Sequence Analysis, DNA
D019081:O Antigens; D016695:Glycosyltransferases; C086735:heptosyltransferase; C080934:lipooligosaccharide 1,5-heptosyltransferase