The optional E. coli prr locus encodes a latent form of phage T4-induced anticodon nuclease.
The optional Escherichia coli prr locus restricts phage T4 mutants lacking polynucleotide kinase or RNA ligase. Underlying this restriction is the specific manifestation of the T4-induced anticodon nuclease, an enzyme which triggers the cleavage-ligation of the host tRNALys. We report here the molecular cloning, nucleotide sequence and mutational analysis of prr-associated DNA. The results indicate that prr encodes a latent form of anticodon nuclease consisting of a core enzyme and cognate masking agents. They suggest that the T4-encoded factors of anticodon nuclease counteract the prr-encoded masking agents, thus activating the latent enzyme. The encoding of a tRNA cleavage-ligation pathway by two separate genetic systems which cohabitate E. coli may provide a clue to the evolution of RNA splicing mechanisms mediated by proteins.
Department of Biochemistry, Tel Aviv University, Ramat Aviv, Israel.
R
R
Levitz
D
D
Chapman
M
M
Amitsur
R
R
Green
L
L
Snyder
G
G
Kaufmann
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004252:DNA Mutational Analysis; D004789:Enzyme Activation / Q000235:genetics; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics; D008969:Molecular Sequence Data; D012326:RNA Splicing / Q000235:genetics; D012329:RNA, Bacterial / Q000378:metabolism*; D012260:Ribonucleases / Q000235:genetics* / Q000378:metabolism; D013604:T-Phages / Q000235:genetics*
D012329:RNA, Bacterial; D012260:Ribonucleases; C049345:anticodon nuclease