Identification of critical residues in Hepatitis E virus macro domain involved in its interaction with viral methyltransferase and ORF3 proteins.
Hepatitis E virus (HEV) is a major cause of hepatitis in normal and organ transplant individuals. HEV open reading frame-1 encodes a polypeptide comprising of the viral nonstructural proteins as well as domains of unknown function such as the macro domain (X-domain), V, DUF3729 and Y. The macro domain proteins are ubiquitously present from prokaryotes to human and in many positive-strand RNA viruses, playing important roles in multiple cellular processes. Towards understanding the function of the HEV macro domain, we characterized its interaction partners among other HEV encoded proteins. Here, we report that the HEV X-domain directly interacts with the viral methyltransferase and the ORF3 proteins. ORF3 association with the X-domain was mediated through two independent motifs, located within its N-terminal 35aa (amino acids) and C-terminal 63-123aa. Methyltransferase interaction domain was mapped to N-terminal 30-90aa. The X-domain interacted with both ORF3 and methyltransferase through its C-terminal region, involving 66(th),67(th) isoleucine and 101(st),102(nd) leucine, conserved across HEV genotypes. Furthermore, ORF3 and methyltransferase competed with each other for associating with the X-domain. These findings provide molecular understanding of the interaction between the HEV macro domain, methyltransferase and ORF3, suggesting an important role of the macro domain in the life cycle of HEV.
Virology Laboratory, Vaccine and Infectious Disease Research Centre, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, P O Box No. 04, Faridabad-121001, Haryana, India.
Saumya
S
Anang
Virology Laboratory, Vaccine and Infectious Disease Research Centre, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, P O Box No. 04, Faridabad-121001, Haryana, India.
Chandru
C
Subramani
Virology Laboratory, Vaccine and Infectious Disease Research Centre, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, P O Box No. 04, Faridabad-121001, Haryana, India.
Vidya P
VP
Nair
Virology Laboratory, Vaccine and Infectious Disease Research Centre, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, P O Box No. 04, Faridabad-121001, Haryana, India.
Sheetal
S
Kaul
Virology Laboratory, Vaccine and Infectious Disease Research Centre, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, P O Box No. 04, Faridabad-121001, Haryana, India.
Nidhi
N
Kaushik
Centre for Bio-design &Diagnostics, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, P O Box No. 04, Faridabad-121001, Haryana, India.
Chandresh
C
Sharma
Centre for Bio-design &Diagnostics, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, P O Box No. 04, Faridabad-121001, Haryana, India.|Experimental Medicine and Biotechnology Department, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, India.
Ashutosh
A
Tiwari
Virology Laboratory, Vaccine and Infectious Disease Research Centre, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, P O Box No. 04, Faridabad-121001, Haryana, India.
C T
CT
Ranjith-Kumar
Virology Laboratory, Vaccine and Infectious Disease Research Centre, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, P O Box No. 04, Faridabad-121001, Haryana, India.
Milan
M
Surjit
D004252:DNA Mutational Analysis; D016752:Hepatitis E virus / Q000235:genetics / Q000502:physiology*; D006801:Humans; D020815:Polyproteins / Q000378:metabolism*; D011485:Protein Binding; D025941:Protein Interaction Mapping; D014764:Viral Proteins / Q000378:metabolism*
D020815:Polyproteins; D014764:Viral Proteins