| lack of canonical e6 and e7 open reading frames in bird papillomaviruses: fringilla coelebs papillomavirus and psittacus erithacus timneh papillomavirus. | determination and analyses of the complete sequence of fringilla coelebs papillomavirus and psittacus erithacus timneh papillomavirus indicate that they represent a distinct and distant lineage of papillomaviruses. the lack of canonical e6-e7 open reading frames suggests that they serve adaptive functions during papillomavirus evolution. | 2002 | 12208979 |