A partial restriction map of the proA-purE region of the Escherichia coli K12 chromosome.

EcoRI restriction mapping data for fragments larger than 0.7 kb and contained in a 350-kb region of the Escherichia coli K-12 chromosome are presented. 75% of these fragments have been located relative to proA, B, argF, lac, proC, purE, and various insertion sequence elements normally present in this region. BglII and BamHI maps for the regions near argF and purE are also provided.

Specificity in the formation of delta tra F-prime plasmids.

Twenty-three independent delta tra F-prime plasmids from three different Escherichia coli K-12 sublines were isolated from Hfr strains whose points of origin coincided with the IS3 element alpha 3 beta 3 or alpha 4 beta 4 in the lac-purE region of the E. coli chromosome. Electrophoretic analysis of plasmid deoxyribonucleic acid digested with EcoRI and hybridization analysis of plasmid deoxyribonucleic acid digested with BglII revealed that at least 14 of these plasmids were formed by processes involving specific bacterial and F loci. Two of the specific bacterial loci involved in delta tra F-prime formation were located at approximately 3.3 and 11.7 min on the E. coli chromosomal map. Two of the delta tra F-prime plasmids contained bacterial deoxyribonucleic acid with circularization endpoints that mapped very near the termini of the IS2 element that is normally located between lac and proC.

Sexual adjustment and feminine attractiveness among spinal cord injured women.

Responses to semistructured interviews with 31 spinal cord injured women yielded sexual adjustment scores and material concerning sexual compensation and orgasm, bowel and bladder programs, and methods of enhancing attractiveness. Sexual adjustment scores were unrelated to time since injury. Few subjects reported the need to make special provision to control elimination during sexual activity. Openness and honesty with mates were stressed. Those with high sexual-adjustment scores compensated for lost sensation and mobility. Orgasm descriptions and most attractiveness-related behaviors resembled those of able-bodied women; some attractiveness behaviors specifically compensated for disability.

Specificity in formation of type II F' plasmids.

Eight new F' plasmids derived from Hfr strains in which F is integrated at the chromosomal element alpha 3 beta 3 have been isolated and subjected to restriction enzyme, hybridization, and electron microscope heteroduplex analysis. Plasmids carrying extensive amounts of bacterial deoxyribonucleic acid were produced even though they were obtained by selection for transfer of lac, which is closely linked to F in the parental Hfr strains. Seven plasmids were type II Flac+ proC+ purE+ plasmids, and one was a type I Flac+ proC+ plasmid. Five of the Flac+ proC+ purE+ plasmids contain approximately 284 kilobases of bacterial deoxyribonucleic acid, which is identical for all five within the resolution of the restriction enzyme analysis. Theses results indicate that type II F' plasmids are the predominant tra+ F' type from this region of the Escherichia coli K-12 chromosome and that the recombination events leading to formation of these plasmids exhibit site specificity.

A plasmid sequence from Rhizobium leguminosarum 300 contains homology to sequences near the octopine TL-DNA right border.

The DNA sequence from a Rhizobium leguminosarum 300 (RL300) plasmid that contains homology to the Tc-DNA of Agrobacterium tumefaciens is described. The RL300 sequence has 78% homology to a 359 bp sequence in the Tc-DNA of pTi15955. The RL300 homology starts approximately 100 bp from the 24 bp border sequence of the TL-DNA and ends approximately 3 bp from an IS66 homolog in the Tc-DNA. An unusual feature of the RL300 homology is the presence of 81 bp direct repeats with Tc-DNA homology, separated by 201 bp. One end of each direct repeat has a 12 bp palindrome. Four cloned sequences of RL300 with homology to the T DNA region were hybridized to plasmid lysates of RL300 derivatives to determine the source of each plasmid. The sequenced homolog, originally on pRH228, was isolated from pRL7JI; the other 3 homologs were isolated from the transmissable plasmids pRL7JI (pRH235) and pRL8JI (pRH235 and pRH236).

Conservation of DNA regions adjacent to nifKDH homologous sequences in diverse slow-growing Rhizobium strains.

Restriction endonuclease-digested deoxyribonucleic acid (DNA) from 17 slow-growing Rhizobium strains was hybridized with 32P-labeled DNA of the Klebsiella pneumoniae nitrogenase structural gene (nifKDH) region. Sixteen of these strains contained two or more fragments that were homologous to K. pneumoniae nifKDH after cleavage with EcoRI or HindIII. Hybridization with nifKDH subclones revealed that most of the Rhizobium fragments were homologous to the HindIII-EcoRI portion of nifKDH (corresponding to the nifDH region), although fragments homologous to the EcoRI-HindIII portion of nifKDH (corresponding to the nifK region) were also present. Comigrating nif-homologous restriction endonuclease fragments were observed for strains isolated from different geographic locations and from nodules of different plant species. Nearly identical hybridization patterns were obtained for five R. japonicum strains which clearly differed in the pattern of restriction endonuclease fragments from their chromosomal DNA. This indicates that there is a high degree of conservation of DNA sequence surrounding the region of nif homology in these strains.

Enumeration and identification of IS3 elements in Escherichia coli strains.

Escherichia coli K-12 strains ordinarily contain five IS3 elements. Three of these correspond to previously mapped IS3 elements (R. C. Deonier, G. R. Oh, and M. Hu, J. Bacteriol. 129:1129--1140, 1977; S. Hu, E. Ohtsubo, and N. Davidson, J. Bacteriol. 122:749--763, 1975), and two additional IS3 elements are identified. The distribution of IS3 elements among deoxyribonucleic acid fragments generated by digestion with EcoRI indicates a basic pattern from which deviation is detected.

Expression of genes from the marine bacterium Alteromonas haloplanktis 214 in Escherichia coli K-12.

DNA from the marine bacterium Alteromonas haloplanktis 214 was partially digested with Sau 3A and inserted into the Bam HI site of the cloning vector pBR322. The ligation mixture was used to transform Escherichia coli HB101. The gene bank plasmid preparation obtained was used to transform Escherichia coli K-12 strain EO2717, an organism auxotrophic for histidine, arginine, adenine, uracil and thiamin. Prototrophic transformants for each of the five metabolites were isolated using appropriate minimal media for selection. Plasmids isolated from each of the transformants were shown by hybridization to contain A. haloplanktis DNA and to be capable of complementing the appropriate mutation in E. coli EO2717. Restriction maps showed that each of the plasmids was different.