Human parainfluenza virus type 2 L protein regions required for interaction with other viral proteins and mRNA capping.
The large RNA polymerase (L) protein of human parainfluenza virus type 2 (hPIV2) binds the nucleocapsid, phosphoprotein, and V protein, as well as itself, and these interactions are essential for transcription and replication of the viral RNA genome. Although all of these interactions were found to be mediated through the domains within the N terminus of L, the C terminus of the L protein was also required for minigenome reporter gene expression. We have identified a highly conserved rubulavirus domain near the C terminus of the L protein that is required for mRNA synthesis but not for genome replication. Remarkably, this region of L shares homology with a conserved region of cellular capping enzymes that binds GTP and forms a lysyl-GMP enzyme intermediate, the first step in the cellular capping reaction. We propose that this conserved region of L also binds GTP (or GDP) to carry out the second step of the unconventional nonsegmented negative-strand virus capping reaction.
Department of Microbiology, Mie University Graduate School of Medicine, 2-174, Edobashi, Tsu, Mie 514-8507, Japan. nishio@doc.medic.mie-u.ac.jp
Machiko
M
Nishio
Masato
M
Tsurudome
Dominique
D
Garcin
Hiroshi
H
Komada
Morihiro
M
Ito
Philippe
P
Le Mercier
Tetsuya
T
Nosaka
Daniel
D
Kolakofsky
D002460:Cell Line; D006801:Humans; D010223:Parainfluenza Virus 2, Human / Q000235:genetics / Q000502:physiology*; D011485:Protein Binding; D012315:RNA Caps / Q000378:metabolism; D012323:RNA Processing, Post-Transcriptional; D012333:RNA, Messenger / Q000378:metabolism*; D012367:RNA, Viral / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*; D014779:Virus Replication
D012315:RNA Caps; D012333:RNA, Messenger; D012367:RNA, Viral; D014764:Viral Proteins; C069129:L protein, Human parainfluenza virus 2