its mylife aqmar: M13 Phage

M13 is a filamentous bacteriophage composed of circular single stranded DNA (ssDNA) which is 6407 nucleotides long encapsulated in approximately 2700 copies of the major coat protein P8, and capped with 5 copies of two different minor coat proteins (P9, P6, P3) on the ends.The phage coat is primarily assembled from a 50 amino acid protein called pVIII (or p8), which is encoded by gene VIII (or g8) in the phage genome.The general stages to a viral life cycle are: infection, replication of the viral genome, assembly of new viral particles and then release of the progeny particles from the host. Filamentous phage use a bacterial structure known as the F pilus to infect E. coli, with the M13 p3 tip contacting the TolA protein on the bacterial pilus. The phage genome is then transferred to the cytoplasm of the bacterial cell where resident proteins convert the single stranded DNA genome to a double stranded replicative form ("RF"). This DNA then serves as a template for expression of the phage genes.Below are steps involved with replication of M13 in E. coli. :-Viral (+) strand DNA enters cytoplasm.Complementary (-) strand is synthesized by bacterial enzymes.DNA Gyrase, a type II topoisomerase, acts on double-stranded DNA and catalyzes formation of negative supercoils in double-stranded DNA.Final product is parental replicative form (RF) DNA.A phage protein, pII, nicks the (+) strand in the RF.3'-hydroxyl acts as a primer in the creation of new viral strand.pII circulizes displaced viral (+) strand DNA..Pool of progeny double-stranded RF molecules produced.Negative strand of RF is template of transcription.mRNAs are translated into the phage proteins.
Source:http://microbiologycenter.blogspot.com/2013/08/m13-phage.html

M13 Phage Images