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A cryptic lysis gene near the start of the Qβ replicase gene in the +1 frame
Author(s) -
Nishihara Tohru,
Morisawa Hirokazu,
Ohta Norihito,
Atkins John F.,
Nishimura Yukinobu
Publication year - 2004
Publication title -
genes to cells
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.912
H-Index - 115
eISSN - 1365-2443
pISSN - 1356-9597
DOI - 10.1111/j.1365-2443.2004.00778.x
Subject(s) - biology , gene , frameshift mutation , rna dependent rna polymerase , lysis , microbiology and biotechnology , gene product , translational frameshift , rna , escherichia coli , ribosomal binding site , ribosome , mutant , genetics , mutation , gene expression
The maturation/lysis (A2) protein encoded by the group B single‐stranded RNA bacteriophage Qβ mediates lysis of host Escherichia coli cells. We found a frameshift mutation in the replicase (β‐subunit) gene of Qβ cDNA causes cell lysis. The mutant has a single base deletion 73 nucleotides (nt) 3′ from the start of the replicase gene with consequent translation termination at a stop codon 129–131 nt further 3′. The 43‐amino acid C‐terminal part of the 67‐amino acid product encoded by what in WT (wild‐type) is the +1 frame, is rich in basic amino acids This 67‐aa protein can mediate cell lysis whose characteristics indicate that the protein may cause lysis by a different mechanism and via a different target, than that caused by the A2 maturation/lysis protein. Synthesis of a counterpart of the newly discovered lysis product in wild‐type phage infection would require a hypothetical ribosomal frameshifting event. The lysis gene of group A RNA phages is also short, 75 codons in MS2, and partially overlaps the first part of their equivalently located replicase gene, raising significant evolutionary implications for the present finding.