Identification and Characterization of Structural Proteins in the Complex Phage 201phi2-1 by Mass Spectrometry

摘要

Tailed phages are bacterial viruses that consist of an outer protein icosahedral-shaped head, or capsid, (that contains the double-stranded DNA genome) and a tail. Phage 201phi2-1 is a large phage infective for Pseudomonas chlororaphis that was isolated from a Texan soil sample. Morphological features of 201phi2-1 include a contractile tail and a complex baseplate, features that are typical of myoviruses (phages with contractile tails, such as T4). More unusual morphological features of 201phi2-1 include an inner body within its head and a large number of fine tail sheath fibers (Figure 1). The genome of phage 201phi2-1 is extremely long, 316,674 bp. This is more than six times the length of lambda phage (48,502 bp) and is predicted to encode over 460 proteins. However, it has not been possible to identify the functions of most of these proteins by sequence comparison (Thomas et al., 2008).