Model for arrangement of minor structural proteins in head of bacteriophage λ
Abstract
THE morphogenesis and maturation of the head of bacteriophage λ requires the function of 10 phage genes1-5, with the products of five of these genes, E, D, FII, B and C, present as structural components of the head4,6,7. The first three of these head proteins are found intact in the phage; the products of genes E and D, pE and pD, form the outer shell of the capsid6, and pFII is thought to form part of the head-tail connector7. The other two gene products pB and pC undergo extensive alterations during head assembly. pC is fused to a minor fraction of pE and is cleaved to form two polypeptides, X1 and X2, which differ only in the length of the pC fragment present8. There are between three and nine molecules of each of these proteins in the phage head6. The product of gene B, pB, is also cleaved during head assembly to form pB* (refs 4-6). There are between 10 and 14 molecules of pB* in the phage3,6. Since an icosahedron has 12 corners, it has been suggested that 12 pB* molecules are structural components of the corners of the viral capsid9,11.
- Publication:
-
Nature
- Pub Date:
- October 1975
- DOI:
- 10.1038/257815a0
- Bibcode:
- 1975Natur.257..815M