Characterization of proteins and nucleic acids after colitis phage infection

Abstract

Colitis phage has a growth cycle of 35 min with a burst size of 100. Analysis of structural proteins of the purified phage showed the presence of four major polypeptides of molecular weights 67,000, 48,000, 39,800 and 26,600. The phage DNA was found to be double stranded and of molecular weight 10 × 10 super(6) with G+C content of 53.5%. Synthesis of DNA, RNA and protein started at 4-5 min, nucleic acids reached maxima at 20 min while protein reached maximum at 35 min after infection. The host transcription and translation were arrested by 6 min as determined by the induction of beta -galactosidase and host DNA was degraded by 10 min after infection. Pulse-labelling experiments showed that synthesis of 4-5 S RNAs started after 5 min and that of a high molecular weight RNA after 11 min after infection. Finger printing of 4-5 S RNA showed modification of host RNA and/or synthesis of phage-specific RNA.