RT Journal Article SR Electronic(1) A1 Hwang, Wen-Ling A1 Su, Tsung-ShengYR 1998 T1 Translational regulation of hepatitis B virus polymerase gene by termination-reinitiation of an upstream minicistron in a length-dependent manner JF Journal of General Virology, VO 79 IS 9 SP 2181 OP 2189 DO https://doi.org/10.1099/0022-1317-79-9-2181 PB Microbiology Society, SN 1465-2099, AB Hepatitis B virus (HBV) polymerase (P) gene is translated from the bicistronic pregenomic RNAwith the core (C) gene in the first cistron. The P ORF is preceded by the C AUG and three AUG codons within the C region, where a minicistron of 7 amino acids can potentially be translated. Our results indicate that the efficiency of the P gene translation initiation was about 10% of that of the C gene when both genes were fused in-frame to a lacZ reporter in an mRNA similar in structure to the pregenomic RNA. By mutational analysis, about 74% of the translation initiation of HBV P gene was shown to be by ribosomes that reinitiated after terminating translation of this minicistron, while the rest was by two mechanisms: one by ribosomes leaky scanning through every upstream AUG and the other by ribosomal backwards scanning to the P AUG after finishing the translation of the C gene. The efficiency of termination-reinitiation depended on the size of the minicistron, i.e. the reinitiation efficiency decreased about 50% when the size increased from 24 nt to 57 nt. When a 44 nt HBV sequence comprising the minicistron was inserted at the 5′ untranslated region of the cat gene, CAT expression was regulated in a similar way to that of the HBV P gene. Moreover, when transfection occurred with an HBV expression plasmid containing an inactivated minicistron, production of virus-like particles dropped to about one-third of the wild-type level, suggesting that the termination-reinitiation mechanism is indeed important for HBV P gene expression., UL https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-79-9-2181