Coronavirus genome: prediction of putative functional domains in the non-structural polyprotein by comparative amino acid sequence analysis

摘要: Amino acid sequences of 2 giant non-structural polyproteins (F1 and F2) infectious bronchitis virus (IBV), a member Coronaviridae, were compared, by computer-assisted methods, to number other positive strand RNA viral cellular proteins. By this approach, juxtaposed putative RNA-dependent polymerase, nucleic binding ("finger"-like) helicase domains identified in F2. Together, these might constitute the core protein complex involved primer-dependent transcription, replication recombination coronaviruses. In F1, two cysteine protease-like growth factor-like one revealed. One proteases IBV is similar 3C picornaviruses related enzymes como- nepo- potyviruses. Search F1 F2 for sites those cleaved latter intercomparison surrounding sequence stretches revealed 13 dipeptides Q/S(G) which are probably coronavirus 3C-like protease. Based on observations, partial tentative scheme functional organization expression strategy was proposed. It implies that, despite general similarity viruses, particularly potyviruses, coronaviruses possess unique structural features.