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Biomedical subjects

Y Otsuki

Publications and source records attributed to Y Otsuki.

At least 91 records · Page 5Linked to original sources
PubMed1978

Kinetics of biphasic reconstitution of tobacco mosaic virus in vitro.

The kinetics of the in vitro reconstitution of tobacco mosaic virus from its RNA and protein were studied by measuring the increase in turbidity, the development of ribonuclease-resistant infectivity, the emcapsidation of the terminal ends of the RNA, and the growth of rod length. The results showed that the reconstitution reaction consists of two processes in which the direction, timing, and rate of assembly are different. Rapid elongation of particles toward the 5' end of the RNA proceeds in the first 5-7 min to give intermediate particles of 260 nm in length in which only the 5' terminus of the RNA is encapsidated. The subsequent process requires 30-50 min, is accompanied by a slow increase in turbidity, and gives rise to rods of the full length, 300 nm. The 3' terminus becomes RNase resistant by this process with concomitant development of ribonuclease-resistant infectivity, showing that the 3'-distal portion of the RNA is encapsidated in the direction of 5' to 3'. The rate of rod elongation by the second process is less than 1/10 of that by the first process.

Capsid↗
PubMed1977

Reconstitution of tobacco mosaic virus rods occurs bidirectionally from an internal initiation region: demonstration by electron microscopic serology.

RNA of a common strain of tobacco mosaic virus was sequentially reconstituted first with protein of the same strain and then with protein of a tomato strain. The reconstituted particles were treated with specific antibodies against the two strain particles and were examined electron microscopically to locate the regions of rods encapsidated with the respective proteins. The results demonstrated that reconstitution starts at an internal region of the RNA about 830 nucleotides from an end that recent studies indicate to be the 3' terminus. Evidence was obtained to show that reconstitution proceeds toward the 5' terminus of the RNA until it is fully encapsidated. Encapsidation of the 3' distal portion of the RNA apparently occurs later and in a direction opposite to that of the encapsidation of the 5' distal portion.

Binding Sites↗