TY - JOUR
T1 - The G23 and G25 genes of temperate mycobacteriophage L1 are essential for the transcription of its late genes
AU - Datta, Hirock Jyoti
AU - Mandal, Prajna
AU - Bhattacharya, Rajat
AU - Das, Niranjan
AU - Sau, Subrata
AU - Mandal, Nitai Chanda
PY - 2007/3
Y1 - 2007/3
N2 - Two lysis-defective but DNA synthesis non-defective temperature-sensitive (ts) mutants of mycobacteriophage L1, L1G23ts23 and L1G25ts889 were found to be defective also in phage-specific RNA synthesis in the late period of their growth at 42°C, each to the extent of 50% of that at 32°C. The double mutant, L1G23ts23G25ts889 showed the ts defect in phage RNA synthesis that was nearly additive of those shown individually by the two single-mutant parents. Both G23 and G25 were shown to start functioning sometimes between 30 and 45 min after infection but the former gene might be dispensable after 45 min, while the latter was not. Northern analysis also shows that at 42°C, L1G23ts23 affects RNA synthesis more strongly than L1G25ts889 from L1 DNA segments that serve as the template for late gene transcription. Among the 21 virion and 12 non-virion late proteins synthesized by L1, L1G23ts23 is defective in the synthesis of at least 9 virion and all of non-virion proteins at 42°C. In contrast, L1G25ts889 is completely defective in synthesis of all the 33 late proteins. Possible roles of G23 and G25 in the positive regulation of transcription of different sets of late genes of L1 have been discussed.
AB - Two lysis-defective but DNA synthesis non-defective temperature-sensitive (ts) mutants of mycobacteriophage L1, L1G23ts23 and L1G25ts889 were found to be defective also in phage-specific RNA synthesis in the late period of their growth at 42°C, each to the extent of 50% of that at 32°C. The double mutant, L1G23ts23G25ts889 showed the ts defect in phage RNA synthesis that was nearly additive of those shown individually by the two single-mutant parents. Both G23 and G25 were shown to start functioning sometimes between 30 and 45 min after infection but the former gene might be dispensable after 45 min, while the latter was not. Northern analysis also shows that at 42°C, L1G23ts23 affects RNA synthesis more strongly than L1G25ts889 from L1 DNA segments that serve as the template for late gene transcription. Among the 21 virion and 12 non-virion late proteins synthesized by L1, L1G23ts23 is defective in the synthesis of at least 9 virion and all of non-virion proteins at 42°C. In contrast, L1G25ts889 is completely defective in synthesis of all the 33 late proteins. Possible roles of G23 and G25 in the positive regulation of transcription of different sets of late genes of L1 have been discussed.
KW - Bacteriophage
KW - Late regulatory genes of L1
KW - Late transcription of L1
KW - Mycobacteriophage L1
KW - The G23 and G25 genes of L1
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U2 - 10.5483/bmbrep.2007.40.2.156
DO - 10.5483/bmbrep.2007.40.2.156
M3 - Article
C2 - 17394764
AN - SCOPUS:34047190839
SN - 1225-8687
VL - 40
SP - 156
EP - 162
JO - Journal of Biochemistry and Molecular Biology
JF - Journal of Biochemistry and Molecular Biology
IS - 2
ER -