The Hha protein from Escherichia coli is highly similar (82%) to the YmoA protein from Yersinia enterocolitica. Both are members of a new class of proteins that modulates gene expression, probably by influencing DNA topology. In this paper, complementation of the hha mutation in E. coli by the ymoA gene from Y. enterocolitica has been studied. We show that the ymoA gene complements one of the phenotypic properties of hha mutants (high level of haemolysin production when they carry the recombinant plasmid pANN202-312) when cloned in a medium-copy-number plasmid but not when carried in a low-copy-number plasmid. Western blot analysis of the expression of YmoA in E. coli rules out inefficient expression of the protein. Surprisingly, the hha gene itself fails to complement the hha mutation when cloned in a medium-copy-number vector and causes genetic rearrangements of the E. coli chromosome as a consequence of insertion sequences mobilization.
BlancoA., JuárezA., PastorF. I. J.1991; Overproduction of a Clostridium cellulolyticum endoglucanase by mutant strains of Escherichia coli. FEMS Microbiol Eett 81:221–226
BolivarF., RodríguezR.L., GreenP. J., BetlachM. C., HeynekerH. L., BoyerH. W., CrosaJ. H., FalkowS.1977; Construction and characterization of new cloning vehicles. II. A multipurpose cloning system. Gene 2:95–113
CarmonaM., BalsalobreC., Muñoa, F., MouriñoM., JubeteY., De la CruzF., JuárezA.1993; Escherichia coli hha mutants, DNA supercoiling and expression of the haemolysin genes from the recombinant plasmid pANN202-312. Mol Microbiol 9:1011–1018
CornelisG. R., SluitersC., DelorI., GelbD., KaningaK., Lambert de RouvraitC., SoryM. P., VanooteghemJ. C., MichaelisT.1991; ymo A, a Yersinia enterocolitica chromosomal gene modulating the expression of virulence functions. Mol Microbiolb1023–1034
CunninghamT. P., MontelaroR. C., RushlowK. E.1993; Lentivirus envelope sequences and proviral genomes are stabilized in Escherichia coli when cloned in low-copy-number plasmid vectors. Gene 9:93–98
De la CruzF., CarmonaM., JuárezA.1992; The Hha protein from Escherichia coli is highly homologous to the Ymo A protein from Yersinia enterocolitica. Mol Microbiol 6:3451–3452
GodessartN., MuñoaF. J., ReguéM., JuárezA.1988; Chromosomal mutations that increase the production of a plasmid- encoded haemolysin in Escherichia coli. J Gen Microbiol 134:2779–2787
GoebelW., HedgepthJ.1982; Cloning and functional characterization of the plasmid-encoded haemolysin determinant of Escherichia coli. J Bacteriol 151:1290–1298
HultonC.S.J., SeirafiA., HintonJ. C. D., SidebothamJ. M., WaddellL., PawitG. D., Owen-HughesT., SpasskyA., BueH., HigginsC. F.1990; Histone-like protein HI (H-NS), DNA supercoiling and gene expression in bacteria. Cell 63:631–642
NietoJ. M., TomásJ, JuárezA.1987; Secretion of an Aeromonas hydrophila aerolysin by a mutant strain of Escherichia coli. FEMS Microbiol Lett 48:413–417
NietoJ. M., CarmonaM., BollandS., JubeteY., De la CruzF., JuárezA.1991; The hha gene modulates haemolysin expression in Escherichia coli. Mol Microbiol 5:1285–1293
SimonR., HötteB., KlaukeB., KosierB.1991; Isolation and characterization of insertion sequence elements from gram-negative bacteria by using new broad-host-range, positive selection vectors. J Bacteriol 173:1502–1508
SprattB. G., BoydA., StokerN.1980; Defective and plaque- forming lambda transducing bacteriophage carrying penicillin- binding protein-cell shape genes : genetic and physical mapping and identification of gene products from the lip-dac A-rod A-pbp A-leu S region of the Escherichia coli chromosome. J Bacteriol 143:569–581
SpurioR., DürrenbergerM., FalconiM., La TeanaA., PonC. L., GuatereiC. O.1992; Lethal overproduction of the Escherichia coli nucleoid protein H-NS: ultramicroscopic and molecular autopsy. Mol Gen Genet 231:201–211
UeguchiC., ItoK.1992; Multicopy suppression: an approach to understanding intracellular functioning of the protein export system. J Bacteriol 174:1454–1461
WangR.F., KushnerS. R.1991; Construction of versatile low- copy-number vectors for cloning, sequencing and gene expression in Escherichia coli. Gene 100:195–199