Function and oligomerization study of the leucine zipper-like domain in P13 from Leucania separata multiple nuclear polyhedrosis virus.
The p13 gene is uniquely present in Group II nucleopolyhedroviruses (NPVs) and some granuloviruses, but not in Group I NPVs. p13 gene was first described by our laboratory in Leucania separatamultiple nuclear polyhedrosis virus (Ls-p13) in 1995. However, the functions of Ls-P13 and of its homologues are unknown. When Ls-p13 was inserted into Autographa californica nucleopolyhedrovirus, a Group I NPV, polyhedra yield was inhibited. However, this inhibition was prevented when the leucine zipper-like domain of Ls-p13 was mutated. To determine the cause of this marked difference between Ls-P13 and leucine zipper mutated Ls-P13 (Ls-P13mL), oligomerization and secondary structure analyses were performed. High performance liquid chromatography and yeast two-hybrid assays indicated that neither Ls-P13 nor Ls-P13mL could form oligomers. Informatics and circular dichroism spectropolarimetry results further indicated marked secondary structural differences between Ls-P13 and Ls-P13mL. The LZLD of Ls-P13 has two extended heptad repeat units which form a hydrophobic surface, but it is short of a third hydrophobic heptad repeat unit for oligomerization. However, the mutated LZLD of Ls-P13mL lacks the above hydrophobic surface, and its secondary structure is markedly different. This difference in its secondary structure may explain why Ls-P13mL is unable to inhibit polyhedra yield.
Du
Enqi
E
Nanyang-Rothamsted Joint Laboratory for Insect Biology, Nanyang Normal University, Nanyang 473061, P. R. China.
Yao
Lunguang
L
Xu
Hua
H
Lu
Songya
S
Qi
Yipeng
Y
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002942:Circular Dichroism; D016350:Leucine Zippers; D008969:Molecular Sequence Data; D050505:Mutant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D017924:Nucleopolyhedroviruses / Q000737:chemistry*; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D018411:Spodoptera / Q000821:virology*; D020798:Two-Hybrid System Techniques; D014764:Viral Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
D050505:Mutant Proteins; D014764:Viral Proteins; C097989:p13 protein, Leucania separata nuclear polyhedrosis virus