Insertional Inactivation of trpC in Cloned Bacillus trp Segments: Evidence for a Polar Effect on trpF

contrasting

confidence: 99%

mentioning

confidence: 99%

Regulation of a glutamine amidotransferase subunit from Bacillus subtilis by a cloned trpE gene from Bacillus pumilus

Kane¹,

Hill²

1980

“…The origin of the Chrr gene on the 0.9-Md EcoRI fragment of pPLFHL was pCM194 (11). pCM194 and pSL103 (14) were joined in vitro at the respective HindlIl sites. When this composite plasmid was introduced into strain BR151 by transformation, a rearrangement occurred resulting in a plasmid that was neomycin and chloramphenicol resistant, but lacked the trp complementing activity characteristic of pSL103 ( 14).…”

Section: Materlals and Methodsmentioning

confidence: 99%

Transductional selection of cloned bacteriophage phi 105 and SP02 deoxyribonucleic acids in Bacillus subtilis

Marrero¹,

Lovett²

1980

The Bacillus subtilis temperate bacteriophages phi 105 and SP02 are incapable of transduction of the small, multicopy drug resistance plasmids pUB110 and pCM194. Cloning endonuclease-generated fragments of phi 105 or SP02 DNA into each of the plasmids renders the chimeric derivatives susceptible to transduction specifically by the phage whose deoxyribonucleic acid is present in the chimera. The majority of phage deoxyribonucleic acid fragments identified that render plasmids transducible by phi 105 or SP02 appear to be internal fragments, not fragments containing the cohesive ends. However, the highest overall transduction frequency was observed in SP02-mediated transduction of a derivative of pUB110 containing a 1.6-megadalton EcoRI fragment that likely contains the SP02 cohesive ends (plasmid pPL1010). The transducing activity present in a phi 105 transducing lysate had a buoyant density slightly greater than infectious particles, whereas the majority of transducing particles in an SP02(pPL1010) transducing lysate had a buoyant density slightly less than infectious particles. Although no detectable change in plasmid structure resulted from transduction by phi 105 or SP02, deoxyribonucleic acid isolated from a purified SP02(pPL1010) transducing lysate contained no detectable monomeric pPL1010, but did contain a form of pPL1010 of higher molecular weight than the monomer.

“…Results of deletion mapping and complementation studies, together with regulatory studies of pZAZ167 and pZAZ1l1, indicate that the direction of transcription of the Pseudomonas TS genes is promoter-trpB-hpA. It is interesting that ttpA is also distal to trpB in all other bacteria where the direction of transcription is known; these include members of the genera Escherichia, Salmonella, Serratia, and Bacillus (5,6,11).…”

Section: Resultsmentioning

confidence: 99%

Ordering tryptophan synthase genes of Pseudomonas aeruginosa by cloning in Escherichia coli

Manch¹,

Crawford²

1981

The Pseudomonas aeruginosa tryptophan synthase genes, tipA and t7pB, which are induced by their substrate indoleglycerol phosphate, were cloned along with their controlling region into the BamHI site of pBR322 to produce the 10.7megadalton plasmid pZAZ5. Sall partial digestion and ligation yielded a smaller plasmid, pZAZ167, with the chromosomal insert reduced in size from 8.1 to 3.4 megadaltons. Both pZAZ5 and pZAZ167 display Pseudomonas-like regulation of the trpA and trpB genes. Deletion of an EcoRI fragment or a BgI fragment from pZAZ167 yielded plasmids pZAZ168 and pZAZ169; the former expresses trpB but not tipA, and the latter has lost both activities. A deleted form of pZAZ5 designated pZAZ1O1 was obtained by excising a BgllI-BamHI segment and religating the tip gene segment in the opposite orientation. This plasmid expresses t7pA and tipB constitutively. The physical maps of these plasmids establish the gene order: promoter-t7pB-trpA.