caa a22 4500 386393400 CHVBK 20180307112127.0 cr unu---uuuuu 161130e198910 xx s 000 0 eng 10.1017/S0016672300028457 doi S0016672300028457 pii (NATIONALLICENCE)cambridge-10.1017/S0016672300028457 Clonal analysis of the lac operons from Klebsiella M5a1 and the Lac plasmid (pRE2) from Klebsiella V9A [Elektronische Daten] The chromosomal lac region of the coliform bacterium Klebsiella M5al was cloned into the multicopy plasmid pBR322 to give pHE7 and pHE8. pHE8 contains 12·6 kb of M5al DNA, including its complete lac operon, and pHE7 contains 2·5 kb of M5al DNA and includes the complete lac Y gene and a small segment of lacZ. The M5al operon has the same gene order as the Escherichia coli lac operon. The lac genes of the Lac plasmid of Klebsiella V9A were cloned into pBR322 to give pHE1 and pHE2, of approximately 39 and 43 kb. Both plasmids were unstable in an E. coli RecA- strain, in contrast to the stability of pHE8. Polyacrylamide gel electrophoresis tests suggested that the M5a1 β-galactosidase monomer is about 5% longer, i.e. has about 50 more amino acids, than that of the E. coli Z gene. Tests made on the enzymes coded by the lac operons of M5a1, another Klebsiella strain (V9A) and its resident Lac plasmid, and several Lac+ Enterobacteria, led to the conclusion that only Escherichia coli among the Enterobacteria contains an active lacA gene. Copyright © Cambridge University Press 1989 Hitchin F. E. Institute of Animal Genetics, University of Edinburgh, West Mains Road, Edinburgh EH9 3JN, UK Reeve E. C. R. Institute of Animal Genetics, University of Edinburgh, West Mains Road, Edinburgh EH9 3JN, UK Genetical Research Cambridge University Press 54/2(1989-10), 85-91 0016-6723 54:2<85 1989 54 GRH https://doi.org/10.1017/S0016672300028457 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1017/S0016672300028457 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Hitchin F. E. Institute of Animal Genetics, University of Edinburgh, West Mains Road, Edinburgh EH9 3JN, UK NATIONALLICENCE 700 1- Reeve E. C. R. Institute of Animal Genetics, University of Edinburgh, West Mains Road, Edinburgh EH9 3JN, UK NATIONALLICENCE 773 0- Genetical Research Cambridge University Press 54/2(1989-10), 85-91 0016-6723 54:2<85 1989 54 GRH CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge