A NATURAL LONGER GLYCINE-RICH REGION IN IKE FILAMENTOUS PHAGE CONFERSNO SELECTIVE ADVANTAGE

Filamentous phage infect bacteria bearing pili. The phage protein invo lved in the recognition of pili and subsequent penetration of the phag e into bacteria is the gene 3 protein (g3p). This is a multi-domain pr otein with glycine-rich regions separating some of the domains. Here w e have found an insertion within the glycine-rich domain of the g3p of IKe, a filamentous phage which infects bacteria bearing N pili. Altho ugh this insertion considerably increases the length of the glycine-ri ch domain it has no selective advantage or disadvantage in infection o r production of phage, and can therefore be considered a neutral mutat ion.