Identification and characterization of a novel FstK-like protein from spotted knifejaw iridovirus (genus Megalocytivirus).
Prokaryotes contain many DNA binding proteins with large molecular weights and multiple domains. DNA binding proteins are involved in DNA replication, transcription, and other physiological processes. In this study, a DNA binding protein, containing an Ftsk-like protein (FLP) domain, was cloned and characterized from SKIV-ZJ07, a member of the RSIV-type megalocytivirus, using bioinformatics and molecular biology approaches. SKIV-FLP is 3,762 base pairs long, encodes a viral protein of 1253 amino acid residuals, and contains an Ftsk (or EBV-NA3) and a Grx-2 domain. Virion localization indicated that SKIV-FLP is a major viral structural protein located below the major capsid protein. Laser confocal microscopy showed that SKIV-FLP is a cytoplasm-/nuclear-localized protein. However, the reconstruction experiments demonstrated that SKIV-FLP may contain three nuclear localization signals, each present in FLP-NT (1-380 aa), FtsK domain (380-880 aa), and Grx-2 domain (880-1253 aa). When SKIV-FLP was fused to the Gal-4 DNA-binding domain and co-transfected with L8G5-Luc, SKIV-FLP suppressed L8G5-Luc transcription. As a transcription inhibitor, SKIV-FLP also inhibited the transcription of NF-κB and IFN-γ (a type II IFN) promoter in HEK293T cells, suggesting that SKIV-FLP has a role in evading host immunity.
State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China.
Zhiming
Z
Xiang
State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China.
Shaoping
S
Weng
State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China.
Hemei
H
Qi
State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China; School of Marine Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China.
Jianguo
J
He
State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China. Electronic address: dongchfu@mail.sysu.edu.cn.
Chuangfu
C
Dong
D000595:Amino Acid Sequence; D002460:Cell Line; D003001:Cloning, Molecular; D015870:Gene Expression; D006801:Humans; D017994:Iridovirus / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation; D010802:Phylogeny; D021381:Protein Transport; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D014771:Virion / Q000378:metabolism; D014779:Virus Replication
D014764:Viral Proteins
DNA binding protein; FstK-like protein (FLP); Megalocytivirus; Spotted knifejaw iridovirus; Transcription inhibitor