Influence of human Bocavirus 2 mutation on protein structures of the virus and evolutionary relationships

Abstract

Objective To study the relationship among the genome mutation, viral protein structures and virus evolution of human Bocavirus 2(HBoV2). Methods A method of PCR was applied to detect HBoV2 genome in 205 fecal specimens collected from children who had diarrhea in Ruian region, Zhejiang province, China. HBoV2-positive specimens were chosen to further amplify the HBoV2 genome. All the tertiary structures were predicted using the Swiss-PdbViewer software, and a phylogenetic analysis was performed by the MEGA software (version 5.1). Result The positive rate of HBoV2 PCR detection in the collected 205 fecal specimens was 5.36% (11/205). We obtained a sequence of a nearly full-length HBoV2 genome named as Ruian isolate, which is 5196 bases in length. Alignment of the Ruian HBoV2 sequence with other HBoV2 sequences in GenBank revealed that the new HBoV2 shared 99.79% similarities with the reference genome (GenBank no NC_012042). No mutation was found in the NP1 gene, whereas sense mutation of NS1, VP1 and VP2 gene were found. Residue solvent accessibilities that relates to hydrophobic interactions were changed between the NS1 of the Ruian isolate and the reference isolate. The protein structure and location of H-bonds were different between the NS1 of the Ruian isolate and the reference isolate. The phylogenetic tree shows a clear division of the NS1, which has a potential evolution toward or a closely evolutionary relationship with the NS1 of HBoV4. Conclusion HBoV2 infection was detected in Ruian region, Zhejiang province. We found sense mutations in the HBoV2 genome of Ruian isolate. These mutations may alter HBoV2 protein structures, and may have an evolutionary significance. These findings provide data of HBoV2 genome mutation. Key words: Bocavirus, human; Diarrhea; Mutation; Protein structure, terciary; Evolution