Isolation and structure of the nucleocapsid of HVJ

Hosaka, Yasuhiro

doi:10.1016/0042-6822(68)90223-7

Cited by 62 publications

(32 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…a diameter of 15-18 nm and a length of ;1 ,m (1)(2)(3)(4)(5). They are composed of single-stranded RNA and -2600 viral structural protein subunits (NP) with a molecular weight of t60,000 (6,7).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Conformation of the helical nucleocapsids of paramyxoviruses and vesicular stomatitis virus: reversible coiling and uncoiling induced by changes in salt concentration.

Heggeness¹,

Scheid²,

Choppin³

1980

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

The conformations of the helical nucleocapsids of the paramyxoviruses Sendai virus and simian virus 5, and of a rhabdovirus, vesicular stomatitis virus, have been found to vary extensively with changes in salt concentration. In 10 mM sodium phosphate buffer at pH 7.2, the nucleocapsids are loosely coiled or almost completely extended; with increasing concentrations of NaCl they become more tightly coiled and less flexible. Under isotonic conditions (150 mM) the Sendai virus nucleocapsid is moderately tightly coiled but still curved and apparently flexible, whereas at 400 mM or higher it is very tightly coiled, with the appearance of a rigid rod. These saltdependent changes in conformation were also found with nucleocapsids composed of proteolytically cleaved protein subunits. Because of the effect of salt concentration, and the fact that it may change during the preparation of negatively stained samples for electron microscopy, it was necessary to fix the nucleocapsids before negative staining to preserve their original conformation. The striking changes in nucleocapsid conformation in response to the ionic milieu indicate the plasticity of its helical structure and suggest that changes in the microenvironment of the nucleocapsid could influence its conformation during viral RNA transcription and replication or during virus assembly by budding, processes in which changes in the coiling of the nucleocapsid or its flexibility could be important. The nucleocapsids of paramyxoviruses, such as Sendai virus, simian virus 5 (SV5), and Newcastle disease virus, are single, left-handed, helical structures which, when tightly coiled, have a diameter of 15-18 nm and a length of ;1 ,m (1-5). They are composed of single-stranded RNA and -2600 viral structural protein subunits (NP) with a molecular weight of t60,000 (6, 7). Two other proteins (L and P) are associated with the nucleocapsid and thought to be involved in the viral RNA transcriptase activity (8-12). The nucleocapsids of rhabdoviruses-e.g., vesicular stomatitis (VSV) and rabies viruses-also consist of a single-stranded RNA complexed with a single major structural protein (N) and two associated proteins (NS and L) (13-18). In the VSV virion, the nucleocapsid forms a coil t40 nm in diameter but, when separated from the viral membrane, it is often found in helices of considerably smaller diameter (13-17).The conformation of paramyxovirus nucleocapsids has shown wide variations as observed in the electron microscope. They have been seen to have tightly stacked turns and the overall appearance of relatively stiff rods ;1 ,um in length and also as loosely coiled helices extended to varying degrees (1-7, 19, 20). Proteolytic cleavage of the NP protein has been implicated as one of the causes of such variation in nucleocapsid conformation (6, 21); however, in the course of an electron microscopic study of Sendai virus nucleocapsids, we often observed a wide variation in the degree of coiling of duplicate samples that could not be attributed to this mechanism. When ...

show abstract

mentioning

confidence: 99%

“…Suspensions of formaldehyde-fixed nucleocapsids were placed on grids with carbon-coated Formvar films, washed in distilled water, and negatively stained with 2% phosphotungstic acid adjusted to pH 7. 4 Polyacrylamide Gel Electrophoresis. NaDodSO4/polyacrylamide gel electrophoresis was carried out on 10% gels by the procedure of Laemmli (25).…”

mentioning

confidence: 99%

Conformation of the helical nucleocapsids of paramyxoviruses and vesicular stomatitis virus: reversible coiling and uncoiling induced by changes in salt concentration.

Heggeness¹,

Scheid²,

Choppin³

1980

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…The RNP is a single helical structure and the sense of the helix is left-handed (154). The size of the RNP of various paramyxoviruses has been estimated by many workers and it has been concluded that the modal length is approximately 1 !tm and the width is 17-18 nm with a central hole about 5 nm in diameter (16,30,52). From the number of turns in the helix and the number of subunits per turn, it is calculated that one RNP contains 2,200-2,600 NP subunit molecules.…”

Section: Structure Of the Virionmentioning

confidence: 99%

Assembly of Paramyxoviruses

Matsumoto

1982

Microbiology and Immunology

View full text Add to dashboard Cite

“…Also by means of the rotation technique [5], end-on views of nucleocapsid were analyzed to determine the number of subunits per turn. Fifteen turns suggested by Hosaka [3] were not obtainable. These results suggest that the single helix of length is composed of ellipsoidal substructures with a long axis of 55 A and a short axis of less than 20 A, which is beyond the resolution.…”

mentioning

confidence: 99%

“…For this purpose, a preparation of nucleocapsid weakly stained with phosphotungstic acid was photographed through a focal series to obtain a picture in the exact focus. Both Fushimi and Z strains of Sendai virus propagated in embryonated eggs were purified by differential centrifugation and resuspended in Na.,CO3-NaHCO3 buffer for disintegration with Emasol 1130, following Hosaka's procedure to obtain free nucleocapsid [3]. These nucleocapsid preparations as well as free nucleocapsids in the allantoic fluid were banded by sucrose gradient centrifugation prior to electron microscopy.…”

mentioning

confidence: 99%