| determination of very thin pili by the bacterial drug resistance plasmid r485. | | 1978 | 372971 |
| five control systems preventing transfer of escherichia coli k-12 sex factor f. | the transfer inhibition systems of 28 fin+ plasmids have been characterized, using flac mutants insensitive to inhibition by r100 or r62. all f-like plasmids (except r455) and one n group plasmid determined systems analogous to that of r100; this is designated the finop system. none of these plasmids could supply a finp component of the transfer inhibitor able to replace that of f itself. in addition to the finop and r62 transfer inhibition systems described previously, new systems were encoded ... | 1975 | 1092654 |
| dna segments of the incx plasmid r485 determining replication and incompatibility with plasmid r6k. | the expression of incompatibility properties between the incx plasmids r6k and r485 of escherichia coli was examined. for small autonomously replicating derivatives of both plasmid elements, the requirements for incompatibility expression include a functional r485 replicon and an active r6k beta-origin region. functional r6k alpha and gamma origins are not directly involved in incompatibility expression between r6k and r485. a trans-acting replication system was constructed for plasmid r485. it ... | 1985 | 3006104 |
| an in vivo cointegrate of two plasmids from incompatibility group x. | formation of a recombinant plasmid designated pnh603 was observed when two plasmids from incompatibility group x, the multicopy plasmid pnh602 (a higher-copy-number deletion derivative of r6k) and the oligocopy plasmid r485, coexisted in a single escherichia coli cell. according to its size and its restriction endonuclease cleavage pattern, plasmid pnh603 is a true cointegrate of pnh602 and r485. an insertion-sequence-like element coming from plasmid r485 is supposed to mediate the fusion of bot ... | 1986 | 3021599 |
| isolation and characterization of a higher-copy-number mutant of plasmid r6k. | a stable copy-number mutant (pnh601) of plasmid r6k was isolated by selection for increased resistance to ampicillin determined by this plasmid. the size of the mutant plasmid was found to be unchanged (26 mg/mol) but it is present in 27 copies of pnh601 per e. coli k-12 chromosome which represents a two-fold increase of r6k copy number value. the following genetic properties of pnh601 are reported and compared with those of r6k: conjugative transfer, fertility inhibition of plasmids belonging t ... | 1983 | 6357969 |
| molecular and genetic properties of plasmid r485 conferring resistance to sulphonamides. | | 1982 | 7042907 |
| molecular comparison of the incx plasmids allows division into incx1 and incx2 subgroups. | we have investigated molecular relationships and evolution of plasmids classified genetically to incompatibility (inc) group x, in particular by comparison of plasmids from the pre-antibiotic era (pae) with contemporary r-plasmids. on the basis of restriction analysis, r6k, the best-described and 'prototype' plasmid of the incx group, exhibited little similarity with the other plasmids in this inc group. other contemporary incx r-plasmids exhibited a substantial degree of interrelationship, and ... | 1993 | 8390556 |
| a family of stability determinants in pathogenic bacteria. | a novel segregational stability system was identified on plasmid r485, which originates from morganella morganii. the system is composed of two overlapping genes, stbd and stbe, which potentially encode proteins of 83 and 93 amino acids, respectively. homologs of the stbde genes were identified on the enterotoxigenic plasmid p307 from escherichia coli and on the chromosomes of vibrio cholerae and haemophilus influenzae biogroup aegyptius. the former two homologs also promote plasmid stability in ... | 1998 | 9829958 |