|
|
|
-
PB2 Protein from influenza virus H1N1:
PB2 is one of four proteins which make up the
influenza A virus replication complex. This complex is
responsible for the synthesis of both genomic and messenger
viral RNA, the hereditary and infective agents of the flu virus.
The polymerase complex is also a determinant of both host
specificity and pathogenicity, in other words it helps determine
who gets sick and by how much.
We have compared structural features of bird H5N1 flu virus with
swine H1N1 flu virus. Typically, the presence of two amino acids
-- lysine and asparagine -- at specific sites on the PB2
protein, are required for a bird flu virus to make the jump from
its avian host to replicate efficiently in human cells. However,
the swine flu H1N1 virus lacked both of these amino acid
building blocks.
The structural data compiled by SSGCID reveals changes in the
surface shape of the swine H1N1 virus PB2 protein compared to
that of the avian PB2, differences which could, in turn, affect
factors in the human cell that would otherwise inhibit virus
replication.
The structural data has been published together with biological
data from the group of Dr. Yoshihiro Kawaoka of the University
of Wisconsin-Madison's School of Veterinary Medicine. Dr.
Kawaoka and collaborators found that changes in amino acid
residues (mutations) located on the surface of the “PB2”
polymerase protein are responsible for the H1N1 virus' ability
to adapt to and co-opt human cells.
For more information, please see the Protein Data Bank entries
3KC6,
3KHW and
3L56. The Structure shown is for PB2 from Influenza A virus
strain A/Mexico/InDRE4487/2009(H1N1). See also publication by
Yamada et al. (PLoS Pathogens 5;6(8) (2010)
PDF).
|
|
