Biomaterial Database

Strand exchange in site-specific recombination. 1979

L W Enquist, and H Nash, and R A Weisberg

The site-specific recombination system of phage lambda promotes crossovers at its attachment site (att). In this report we show that when phage are crossed in conditions where only the site-specific recombination system is active, a low frequency of crossovers can also be detected in a region that is close to but does not contain att. These crossovers require the phage int gene, the host hip gene, and the integrity of att. They are not detected if one of the parents carries a substitution of a heterologous attachment site (attB instead of attP). To explain these findings we suggest that site-specific recombination can proceed by exchange of single strands between the participating chromosomes at att and migration of the resulting junction outside of att.

UI	MeSH Term	Description	Entries
D011995	Recombination, Genetic	Production of new arrangements of DNA by various mechanisms such as assortment and segregation, CROSSING OVER; GENE CONVERSION; GENETIC TRANSFORMATION; GENETIC CONJUGATION; GENETIC TRANSDUCTION; or mixed infection of viruses.	Genetic Recombination,Recombination,Genetic Recombinations,Recombinations,Recombinations, Genetic
D003090	Coliphages	Viruses whose host is Escherichia coli.	Escherichia coli Phages,Coliphage,Escherichia coli Phage,Phage, Escherichia coli,Phages, Escherichia coli
D003434	Crossing Over, Genetic	The reciprocal exchange of segments at corresponding positions along pairs of homologous CHROMOSOMES by symmetrical breakage and crosswise rejoining forming cross-over sites (HOLLIDAY JUNCTIONS) that are resolved during CHROMOSOME SEGREGATION. Crossing-over typically occurs during MEIOSIS but it may also occur in the absence of meiosis, for example, with bacterial chromosomes, organelle chromosomes, or somatic cell nuclear chromosomes.	Crossing Over,Crossing-Over, Genetic,Crossing Overs,Genetic Crossing Over,Genetic Crossing-Over
D004926	Escherichia coli	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.	Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli
D005838	Genotype	The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.	Genogroup,Genogroups,Genotypes
D000483	Alleles	Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.	Allelomorphs,Allele,Allelomorph
D013045	Species Specificity	The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.	Species Specificities,Specificities, Species,Specificity, Species