Orientation and interactions of an essential tryptophan (Trp-38) in the capsid subunit of Pf3 filamentous virus.

ABSTRACT: The filamentous bacteriophage Pf3 consists of a covalently closed DNA single strand of 5833 nucleotides sheathed by approximately 2500 copies of a 44-residue capsid subunit. The capsid subunit contains a single tryptophan residue (Trp-38), which is located within the basic C-terminal sequence (-RWIKAQFF) and is essential for virion assembly in vivo. Polarized Raman microspectroscopy has been employed to determine the orientation of the Trp-38 side chain in the native virus structure. The polarized Raman measurements show that the plane of the indolyl ring is tilted by 17 degrees from the virion axis and that the indolyl pseudo-twofold axis is inclined at 46 degrees to the virion axis. Using the presently determined orientation of the indolyl ring and side-chain torsion angles, chi(1) (N-C(

SUBMITTER: Tsuboi M 

PROVIDER: S-EPMC1302766 | biostudies-literature | 2003 Mar

REPOSITORIES: biostudies-literature