The Mycoplasma fermentans prophage φMFV1: genome organization, mobility and variable expression of an encoded surface protein

Abstract

Summary The ≈ 16 kb genome of the Mycoplasma fermentansφMFV1 prophage is described, and its mobility, replication and effect on the mycoplasma surface phenotype are demonstrated. In various M. fermentans strains, φMFV1 was either absent or integrated at diverse (and sometimes multiple) chromosomal sites, each marked by a conserved TTTTTA target sequence that is duplicated upon integration. Precise excision, replication of an extrachromosomal form and loss of φMFV1 from the mycoplasmal genome were documented in a series of clonal derivatives of M. fermentans propagated in culture. Of 18 open reading frames (ORFs) encoded by φMFV1, most can be ascribed functions related to phage biology, whereas one encodes a unique coiled‐coil membrane surface protein, Mem, that was confirmed to be expressed in propagating populations of M. fermentans. With the exception of Mem and other minor ORFs, the striking similarity between the deduced proteomes of φMFV1 and the recently described φMAV1 of arthritogenic strains of Mycoplasma arthritidis, along with the prominent gene synteny between these elements, provides the taxonomic basis for a new family of prophage. Their coding features are consistent with long‐term residence in mycoplasma genomes and the divergence of species within a phylogenetic clade of mycoplasmas. The unique Mem protein expressed from φMFV1 and the unique hypothetical surface lipoproteins encoded by φMAV1 and φMFV1 also suggest that prophage‐associated genes may provide specific, selectable phenotypic traits during co‐evolution of mycoplasma species with their respective mammalian hosts. Retention of these labile prophage elements in organisms with such drastically reduced genome sizes implies a significant role in adaptation and survival.

Identification of a gene in Mycoplasma hominis associated with preterm birth and microbial burden in intraamniotic infection

“…However, strains AF1 and PL5 each harbor a distinct mobile element. A putative prophage in AF1 is 15.2 kb and exhibits similarity to the M. fermentans phiMFV1 prophage 72 . A putative 26.6 kb mobile element in PL5 shares 96% identity with a transposon from Streptococcus agalactiae and other streptococci and enterococci.…”

Analysis of the Complete Mycoplasma hominis LBD-4 Genome Sequence Reveals Strain-Variable Prophage Insertion and Distinctive Repeat-Containing Surface Protein Arrangements

“…hominis PG21 T disclosed colinear chromosomes punctuated by ~78 kb of variation distributed among 20 loci (>250 bp); the largest region of difference was an approximately 15.9-kb prophage genome (designated MHoV-1) related to Mycoplasma arthritidis MAV-1 (9) and Mycoplasma fermentans MFV-1 (10). In M.…”

A Direct Interaction between the Utp6 Half-a-Tetratricopeptide Repeat Domain and a Specific Peptide in Utp21 Is Essential for Efficient Pre-rRNA Processing

“…The UTP6 gene (wild-type or containing the G99E mutation) was cloned into a derivative of the maltose binding protein (MBP) fusion vector pMAL-c2x (New England Biolabs) containing a target site for the tobacco etch virus protease in place of the Factor X protease site (43). MBP, MBP-Utp6-6HIS, and MBP-Utp6-G99E-6HIS were expressed as recombinant proteins in E. coli BL21(DE3) cells using standard methods.…”