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Title: Three-dimensional reconstructions of the bacteriophage CUS-3 virion reveal a conserved coat protein I-domain but a distinct tailspike receptor-binding domain

CUS-3 is a short-tailed, dsDNA bacteriophage that infects serotype K1 Escherichia coli. We report icosahedrally averaged and asymmetric, three-dimensional, cryo-electron microscopic reconstructions of the CUS-3 virion. Its coat protein structure adopts the “HK97-fold” shared by other tailed phages and is quite similar to that in phages P22 and Sf6 despite only weak amino acid sequence similarity. In addition, these coat proteins share a unique extra external domain (“I-domain”), suggesting that the group of P22-like phages has evolved over a very long time period without acquiring a new coat protein gene from another phage group. On the other hand, the morphology of the CUS-3 tailspike differs significantly from that of P22 or Sf6, but is similar to the tailspike of phage K1F, a member of the extremely distantly related T7 group of phages. We conclude that CUS-3 obtained its tailspike gene from a distantly related phage quite recently. - Highlights: • Asymmetric and symmetric three-dimensional reconstructions of phage CUS-3 are presented. • CUS-3 major capsid protein has a conserved I-domain, which is found in all three categories of “P22-like phage”. • CUS-3 has very different tailspike receptor binding domain from those of P22 and Sf6. • The CUS-3 tailspike likely wasmore » acquired by horizontal gene transfer.« less
Authors:
 [1] ; ;  [1] ;  [2] ; ;  [1] ;  [2] ;  [1] ;  [3]
  1. Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093-0378 (United States)
  2. University of Utah School of Medicine, Division of Microbiology and Immunology, Department of Pathology, Salt Lake City, UT 84112 (United States)
  3. (United States)
Publication Date:
OSTI Identifier:
22435053
Resource Type:
Journal Article
Resource Relation:
Journal Name: Virology; Journal Volume: 464-465; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; AMINO ACID SEQUENCE; ASYMMETRY; BACTERIOPHAGES; ELECTRON MICROSCOPY; ESCHERICHIA COLI; GENES; MORPHOLOGY; PROTEIN STRUCTURE; RECEPTORS; SYMMETRY; THREE-DIMENSIONAL CALCULATIONS