S1 attaches the virus to the cell membrane by interacting with host receptor while S2 mediates fusion between the virus and cell membrane , according to Uniprot which provides resources on protein sequence. But it is too early to say how these mutations will affect us, said independent experts.
The paper, led by CSIR Institute of Chemical Biology, Kolkata, and the Academy of Scientific and Innovative Research (AcSIR) in Ghaziabad, said that five sequences from West Bengal have been deposited on the Global Initiative on Sharing All Influenza Data (GISAID) on April 27. Scientists compared the sequences from West Bengal with other sequences reported in India and with isolates of Wuhan origin. Authors explain in their paper which is yet to be peer reviewed published in Medrxiv, a pre-print server for health research that when a virus tries to adapt to a new environment and population it would change its genetic makeup to utilise the host's body in favour of virus's survival and propagation. Broad mutation profile of this protein from extensive genome sequencing from different geographical areas is key to designing effective antiviral therapy or vaccine. While the sequences from West Bengal do tell us they are different from those in Gujarat and Kerala, the knowledge is inadequate in understanding how that can impact virulence or disease.
"There appears to be a new mutation in West Bengal, which ha
sn't been described previously. Some mutations are important while some are not. It's too premature to say anything. The spike protein is a hotspot for mutation. We need some real-life studies of how these mutations change the virus. Some of these mutations may affect the way the virus enters the body," said Dr Shobha Broor, former head of the AIIMS department of virology, who has read the study. "There will be mutations. For example, the Kerala sequence was very similar to the one from Wuhan, the rest were similar to those from Italy. Mutations are critical, depending on where they are happening. For example, the receptor binding area of the RNA is important," she added.