Equinix Inc (Nasdaq:EQIX), a provider of global data centre services, announced on Tuesday that Etsy, an e-commerce marketplace for handmade and vintage goods and supplies, has expanded into Equinix's Silicon Valley SV5
International Business Exchange (IBX) data centre.
Residue 335 (K/E) of MuV HN was located at the third [alpha]-helix ([alpha]3), which seems to be conserved in the secondary structure but not in the amino acid sequence of SV5 and NDV.
All critical amino acids involved in the neuraminidase active site of the crystallized proteins of SV5, NDV and HuPIV-3 were found in both MuV variants, demonstrating the importance of this enzymatic activity for paramyxoviruses (Table 2).
Due to physicochemical differences between these amino acids, it is improbable that the second domain is functional in MuV, as in is the case for the SV5 HN protein, which also possesses P at equivalent residues and does not have the second sialic acid-binding site .
Moreover, all seven cysteines involved in disulfide linkages of template SV5 are conserved in the MuV target model (Figure 2).
The stalk region (residues 1-144) of MuV HN was not modeled because the equivalent amino acids were not visible in the electron density maps of crystallized SV5 HN protein .
Superposition of the predicted HN protein structure of MuV variants over the crystallized HN protein structure of SV5, including the neuraminidase inhibitor DANA (2,3-dehydro-2-deoxy-N-sialic acid or 2-deoxy-2,3-dehydro-nacetylneuraminic acid), permitted the localization of 10 amino acids (R180, D204, E264, Y268, Y303, E407, R422, R512, Y540, E551) that constitute the neuraminidase active site and directly interact with sialic acid.
The precise role of the [alpha]3 helix is unknown; it constitutes part of a structurally variable region that also includes the [alpha]4 helix, the N-terminal region and the loops 452 (424 in SV5) and 493 (476 in SV5), since HuPIV-3, NDV and SV5 HN proteins differ considerably in the spatial distribution of these domains.