A non-canonical multisubunit RNA polymerase encoded by a giant bacteriophage.
The infection of Pseudomonas aeruginosa by the giant bacteriophage phiKZ is resistant to host RNA polymerase (RNAP) inhibitor rifampicin. phiKZ encodes two sets of polypeptides that are distantly related to fragments of the two largest subunits of cellular multisubunit RNAPs. Polypeptides of one set are encoded by middle phage genes and are found in the phiKZ virions. Polypeptides of the second set are encoded by early phage genes and are absent from virions. Here, we report isolation of a five-subunit RNAP from phiKZ-infected cells. Four subunits of this enzyme are cellular RNAP subunits homologs of the non-virion set; the fifth subunit is a protein of unknown function. In vitro, this complex initiates transcription from late phiKZ promoters in rifampicin-resistant manner. Thus, this enzyme is a non-virion phiKZ RNAP responsible for transcription of late phage genes. The phiKZ RNAP lacks identifiable assembly and promoter specificity subunits/factors characteristic for eukaryal, archaeal and bacterial RNAPs and thus provides a unique model for comparative analysis of the mechanism, regulation and evolution of this important class of enzymes.
Peter the Great St. Petersburg Polytechnic University, St. Petersburg, 195251, Russia Department of Molecular Biology and Biochemistry, Waksman Institute, Rutgers, The State University of New Jersey, Piscataway, NJ 08854-8020, USA.
Maria
M
Yakunina
Peter the Great St. Petersburg Polytechnic University, St. Petersburg, 195251, Russia.
Tatyana
T
Artamonova
Peter the Great St. Petersburg Polytechnic University, St. Petersburg, 195251, Russia Rowan University School of Osteopathic Medicine, Stratford, NJ 08084-1501, USA.
Sergei
S
Borukhov
National Center for Biotechnology Information NLM, National Institutes of Health Bethesda, MD 20894, USA.
Kira S
KS
Makarova
Peter the Great St. Petersburg Polytechnic University, St. Petersburg, 195251, Russia Department of Molecular Biology and Biochemistry, Waksman Institute, Rutgers, The State University of New Jersey, Piscataway, NJ 08854-8020, USA Skolkovo Institute of Science and Technology, Skolkovo, 143026, Russia severik@waksman.rutgers.edu.
Konstantin
K
Severinov
Peter the Great St. Petersburg Polytechnic University, St. Petersburg, 195251, Russia Department of Molecular Biology and Biochemistry, Waksman Institute, Rutgers, The State University of New Jersey, Piscataway, NJ 08854-8020, USA minakhin@waksman.rutgers.edu.
Leonid
L
Minakhin
D000595:Amino Acid Sequence; D017124:Conserved Sequence; D012321:DNA-Directed RNA Polymerases / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D059372:Nucleotide Motifs; D011401:Promoter Regions, Genetic; D021122:Protein Subunits / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D017105:Pseudomonas Phages / Q000201:enzymology*; D011550:Pseudomonas aeruginosa / Q000821:virology; D014158:Transcription, Genetic; D014764:Viral Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*
D021122:Protein Subunits; D014764:Viral Proteins; D012321:DNA-Directed RNA Polymerases