Alteration of the ATG start codon of the A* protein of bacteriophage ϕX174 into an ATT codon yields a viable phage indicating that A* protein is not essential for ϕX174 reproduction

FEBS Letters

Jansz, H.S.¹  Baas, P.D.¹  Liewerink, H.¹  van Teeffelen, H.A.A.M.¹  van Mansfeld, A.D.M.¹  van Boom, J.H.² 

[1] Institute of Molecular Biology and Medical Biotechnology and Laboratory for Physiological Chemistry, State University of Utrecht, Padualaan 8, 3584 CH Utrecht, The Netherlands;Department of Organic Chemistry, State University of Leiden, Postbus 9502, 2300 RA Leiden, The Netherlands

关键词: A* protein;    Oligonucleotide-directed mutagenesis;    ATG start codon;    (Bacteriophage ϕX174);    RFI;    replicative form DNA with both strands closed containing superhelical turns;    ss;    single-stranded;    ds;    double-stranded;    c;    circular;   

DOI  :  10.1016/0014-5793(87)81030-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Bacteriophage ϕX174 gene A encodes two proteins: the gene A protein and the smaller A* protein, which is synthesized from a translational start signal within the A gene in the same reading frame as the gene A protein. The gene A protein is involved in initiation, elongation and termination of rolling circle DNA replication. The role of the A* protein in the life cycle of ϕX174, however, is unknown. Using oligonucleotide-directed mutagenesis a viable ϕXl74 mutant was constructed in which the ATG start codon of the A* protein was changed into an ATT codon. This mutant, ϕX-4499T, does not synthesize A* protein. The burst size of ϕX-4499T amounted to 50% of that of wild type ϕXI74. This indicates that A* protein, although advantageous for phage reproduction, is not essential during the life cycle of bacteriophage ϕX174.

【 授权许可】

Unknown