5y2e
From Proteopedia
Crystal structure of the oligomerization domain of NSP4 from the rotavirus strain NCDV
Structural highlights
Function[NSP4_ROTBN] Involved in virus morphogenesis. Functions as a receptor for the immature double-layered inner capsid particle (ICP) which transiently buds into the lumen of the rough endoplasmic reticulum during viral maturation. Enterotoxin that causes a phospholipase C-dependent elevation of the intracellular calcium concentration in host intestinal mucosa cells. Increased concentration of intracellular calcium disrupts the cytoskeleton and the tight junctions, raising the paracellular permeability. Potentiates chloride ion secretion through a calcium ion-dependent signaling pathway, inducing age-dependent diarrhea. To perform this enterotoxigenic role in vivo, NSP4 is probably released from infected enterocytes in a soluble form capable of diffusing within the intestinal lumen and interacting with the plasma membrane receptors on neighboring epithelial cells. Possible receptors for NSP4 are alpha-1/beta-1 and alpha-2/beta-1 integrin heterodimers (By similarity). Publication Abstract from PubMedRotavirus nonstructural protein 4, the first viral enterotoxin to be identified, is a multidomain, multifunctional glycoprotein. Earlier, we reported a Ca(2+)-bound coiled-coil tetrameric structure of the diarrhea-inducing region of NSP4 from the rotavirus strains SA11 and I321 and a Ca(2+)-free pentameric structure from the rotavirus strain ST3, all with a parallel arrangement of alpha-helices. pH was found to determine the oligomeric state: a basic pH favoured a tetramer, whereas an acidic pH favoured a pentamer. Here, we report two novel forms of the coiled-coil region of NSP4 from the bovine rotavirus strains MF66 and NCDV. These crystallized at acidic pH, forming antiparallel coiled-coil tetrameric structures without any bound Ca(2+) ion. Structural and mutational studies of the coiled-coil regions of NSP4 revealed that the nature of the residue at position 131 (Tyr/His) plays an important role in the observed structural diversity. New tetrameric forms of the rotavirus NSP4 with antiparallel helices.,Kumar S, Ramappa R, Pamidimukkala K, Rao CD, Suguna K Arch Virol. 2018 Feb 17. pii: 10.1007/s00705-018-3753-6. doi:, 10.1007/s00705-018-3753-6. PMID:29455326[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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