CHARACTERIZATION OF THE LYSOGENIC BACTERIOPHAGE MAV1 FROM MYCOPLASMA-ARTHRITIDIS

The lysogenic bacteriophage MAV1, which is associated,vith the arthrit ogenicity of Mycoplasma arthritidis, was characterized. Several strain s of M, arthritidis were examined for their ability to support growth of MAV1. A PFU assay was developed, and the sensitivity of phage to va rious chemical treatments was assayed. The most notable result was the resistance of MAV1 to proteinase K. The MAV1 genome is a double-stran ded, linear DNA molecule of about 16 kb. The site of MAV1 DNA integrat ion in the host chromosome was investigated. The ends of MAV1 DNA were cloned from three independent lysogens shown to have MAV1. DNA insert ed at different sites in the host. The nucleotide sequences of the end s of the MAV1 genome and of the MAV1 DNA-chromosomal DNA junctions fro m each of three lysogens were determined. Sequences flanking the integ rated prophage and the ends of native MAV1 DNA were determined, allowi ng the identification of the phage DNA (attP) and bacterial DNA (attB) recombination sites. Analysis of the left MAV1 DNA-chromosomal DNA ju nction sites showed a single-base heterogeneity located within MAV1 DN A sequences immediately adjacent to the attB sequence. A model for MAV 1 integration-excision is proposed.