Reovirus RNA transcriptase: Evidence for a conformational change during activation of the core particle

Powell, K.F.H.; Harvey, J. K.; Bellamy, A R

doi:10.1016/0042-6822(84)90002-3

Cited by 12 publications

(9 citation statements)

References 15 publications

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“…However, transcriptase activity is partially recovered when the protein is reassociated with the cores indicating that more than one protein of the single-capsid particles (including the major one) is required for the enzyme activity, or that the major protein induces a conformational change important for the functioning of the polymerase (Bican et al, 1982). Conformational changes of the reovirus core particle have been recently described during activation of the RNA transcriptase activity (Powell et al, 1984).…”

Section: Discussionmentioning

confidence: 99%

Biochemical Evidence for the Oligomeric (Possibly Trimeric) Structure of the Major Inner Capsid Polypeptide (45K) of Rotaviruses

Gorziglia

Larrea

Liprandi

et al. 1985

Journal of General Virology

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SUMMARYThe major structural polypeptide of rotaviruses is p45K (VP6), which forms the morphological subunit of the inner capsid. Such subunits show a trimeric structure when examined with the electron microscope. Treatment of single-capsid rotavirus particles with 1.5 M-CaCI~ removes p45K, resulting in the generation of smooth cores. Sucrose density gradient centrifugation analysis of the removed p45K revealed that it has a sedimentation coefficient close to 7.3S, compatible with an oligomeric (possibly trimeric) structure. Polyacrylamide gel electrophoresis under reducing or non-reducing conditions indicated that p45K has intramolecular but not intermolecular disulphide bonds, suggesting that interactions between p45K monomers may be due to some other type of association, such as hydrophobic or charge interactions. Velocity sedimentation of infected cell extracts revealed that native p45K also behaves as an oligomeric protein. Such results were confirmed using p45K partially purified by DEAE-cellulose chromatography. The evidence obtained indicated that all p45K present in the virion is in the oligomerie form, not associated by disulphide bonding, and that most native p45K present in the infected cells is also in the oligomeric form, probably as a consequence of early protein-protein interaction in rotavirus morphogenesis.

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Section: Discussionmentioning

confidence: 99%

Biochemical Evidence for the Oligomeric (Possibly Trimeric) Structure of the Major Inner Capsid Polypeptide (45K) of Rotaviruses

Gorziglia

Larrea

Liprandi

et al. 1985

Journal of General Virology

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“…The 3 protein contains the catalytic regions of the RNA polymerase (Koonin, 1992;Starnes and Joklik, 1993). Proteins 2 (Yin et al, 1996) and 1 (Morgan and Kingsbury, 1981;Powell et al, 1984) play apparent roles in transcription as well, perhaps through interactions with 3 (Starnes et al, 1993;Sherry and Blum, 1994;Haller et al, 1995). Proteins 2 and 1 also influence one or more NTPase activities in cores, which may represent the capping RNA triphosphatase and RNA helicase (Rankin et al, 1989;, and/or some other NTP-dependent enzyme for RNA metabolism.…”

Section: Introductionmentioning

confidence: 99%

Internal/Structures Containing Transcriptase-Related Proteins in Top Component Particles of Mammalian Orthoreovirus

et al. 1998

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The structure of mammalian orthoreovirus top component particles, which are profoundly deficient in the content of double-stranded RNA genome, was determined at 30 A resolution by transmission cryoelectron microscopy and three-dimensional image reconstruction. Previously undetected, ordered densities, appearing primarily as pentameric flowers in the reconstruction, were seen to extend 65 A inwardly from the inner capsid at the icosahedral fivefold axes. Identically positioned but lower density elements were observed in two types of partially uncoated top component particles obtained by limited proteolysis. The levels of three inner-capsid proteins-lamda 1, lamda 3, and mu 2-were reduced in concert with the internal densities during proteolytic uncoating. Since lamda 3 contains the catalytic regions of the viral RNA polymerase and since both lamda 1 and mu 2 appear to play roles in transcription or mRNA capping, the internal structures are concluded to be complexes of the viral transcriptase-related enzymes. The findings have implications for the mechanisms of transcription and mRNA capping by orthoreovirus particles.

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“…One possibility is that these holes are so small that they are obscured in the current electron density map (32-Å resolution). Another is that the holes are not opened until conformational changes in the core that accompany active transcription (Powell et al, 1984). In either case, we might expect the sites of mRNA export to be represented by regions of lower density in the current map of the inner capsid of nontranscribing cores.…”

Section: Extending Structure-function Studies Of Mammalian Reovirus Pmentioning

confidence: 99%

IRIS Explorer Software for Radial-Depth Cueing Reovirus Particles and Other Macromolecular Structures Determined by Cryoelectron Microscopy and Image Reconstruction

Spencer

Sgro

Dryden

et al. 1997

Journal of Structural Biology

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Reovirus RNA transcriptase: Evidence for a conformational change during activation of the core particle

Cited by 12 publications

References 15 publications

Biochemical Evidence for the Oligomeric (Possibly Trimeric) Structure of the Major Inner Capsid Polypeptide (45K) of Rotaviruses

Biochemical Evidence for the Oligomeric (Possibly Trimeric) Structure of the Major Inner Capsid Polypeptide (45K) of Rotaviruses

Internal/Structures Containing Transcriptase-Related Proteins in Top Component Particles of Mammalian Orthoreovirus

IRIS Explorer Software for Radial-Depth Cueing Reovirus Particles and Other Macromolecular Structures Determined by Cryoelectron Microscopy and Image Reconstruction

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