Mechanism for coordinated RNA packaging and genome replication by rotavirus polymerase VP1.
Rotavirus RNA-dependent RNA polymerase VP1 catalyzes RNA synthesis within a subviral particle. This activity depends on core shell protein VP2. A conserved sequence at the 3' end of plus-strand RNA templates is important for polymerase association and genome replication. We have determined the structure of VP1 at 2.9 A resolution, as apoenzyme and in complex with RNA. The cage-like enzyme is similar to reovirus lambda3, with four tunnels leading to or from a central, catalytic cavity. A distinguishing characteristic of VP1 is specific recognition, by conserved features of the template-entry channel, of four bases, UGUG, in the conserved 3' sequence. Well-defined interactions with these bases position the RNA so that its 3' end overshoots the initiating register, producing a stable but catalytically inactive complex. We propose that specific 3' end recognition selects rotavirus RNA for packaging and that VP2 activates the autoinhibited VP1/RNA complex to coordinate packaging and genome replication.
Lu
Xiaohui
X
Laboratory of Molecular Medicine, Children's Hospital and Harvard Medical School, Boston, MA 02115, USA.
McDonald
Sarah M
SM
Tortorici
M Alejandra
MA
Tao
Yizhi Jane
YJ
Vasquez-Del Carpio
Rodrigo
R
Nibert
Max L
ML
Patton
John T
JT
Harrison
Stephen C
SC
D001051:Apoenzymes / Q000737:chemistry; D001483:Base Sequence; D001665:Binding Sites; D012321:DNA-Directed RNA Polymerases / Q000737:chemistry*; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D009843:Oligoribonucleotides / Q000737:chemistry; D011487:Protein Conformation; D012367:RNA, Viral / Q000737:chemistry; D012401:Rotavirus / Q000201:enzymology / Q000235:genetics*
D001051:Apoenzymes; D009843:Oligoribonucleotides; D012367:RNA, Viral; D012321:DNA-Directed RNA Polymerases