Characterization of Spodoptera litura multicapsid nucleopolyhedrovirus 38.7 k protein, which contains a conserved BRO domain.
Homology analysis revealed that Spodoptera litura multicapsid nucleopolyhedrovirus (SpltMNPV) 38.7 k protein has 22-83% amino acid identities with Ecotropis obliqua NPV, Mamestra configurata MNPV, Helicoverpa armigera SNPV, H. zea SNPV, S. exigua MNPV and S. littoralis MNPV 38.7 k proteins. Analysis of the relationship of these 38.7 k proteins indicated that they contain a conserved BRO-N domain, and SpltMNPV and SpliMNPV 38.7 k proteins also contain a motif found in all known viral and prokaryotic single-strand DNA binding proteins. RT-PCR results showed that SpltMNPV 38.7 k gene is transcribed actively at the late stage of infection and the mRNA start site was mapped within a consensus baculovirus late promoter motif (ATAAG). Western blot analysis revealed that the 38.7 k was expressed in infected S. litura cells as a 41 kDa form and this protein distributed in the nucleus of infected cells. Using a histone extraction protocol, SpltMNPV 38.7 k could be detected in the histone H1 fraction. Micrococcal nuclease treatment released SpltMNPV 38.7 k protein from the chromatin fraction, suggesting that its involvement in nucleosome structures. Furthermore, column chromatography using DNA-cellulose showed that SpltMNPV 38.7 k protein interacted with nucleic acids. It was proposed that SpltMNPV 38.7 k might function as a DNA-binding protein.
Li
Zhaofei
Z
State Key Laboratory for Biocontrol, Institute of Entomology, Zhongshan University, Guangzhou 510275, PR China.
Pan
Lijing
L
Yu
Hang
H
Li
Lingling
L
Gong
Yingxue
Y
Yang
Kai
K
Pang
Yi
Y
D020816:Amino Acid Motifs / Q000235:genetics; D000818:Animals; D015153:Blotting, Western; D002460:Cell Line; D002467:Cell Nucleus / Q000737:chemistry; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D015870:Gene Expression; D006657:Histones / Q000302:isolation & purification; D017924:Nucleopolyhedroviruses / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000032:analysis; D012367:RNA, Viral; D017386:Sequence Homology, Amino Acid; D018411:Spodoptera / Q000821:virology*; D024363:Transcription Initiation Site; D014764:Viral Proteins / Q000737:chemistry* / Q000235:genetics* / Q000302:isolation & purification / Q000502:physiology
D004268:DNA-Binding Proteins; D006657:Histones; D012333:RNA, Messenger; D012367:RNA, Viral; D014764:Viral Proteins; D004247:DNA