Tomato bushy stunt virus domain

The molecular basis for quasi-equivalent packing was revealed by the very first structure determination to high resolution of a spherical virus, tomato bushy stunt virus. The structure of this T = 3 virus was determined to 2.9 A resolution in 1978 by Stephen Harrison and co-workers at Harvard University. The virus shell contains 180 chemically identical polypeptide chains, each of 386 amino acid residues. Each polypeptide chain folds into distinct modules an internal domain R that is disordered in the structure, a region (a) that connects R with the S domain that forms the viral shell, and, finally, a domain P that projects out from the surface. The S and P domains are joined by a hinge region (Figure 16.8). 

Figure 16.8 Architecture of the tomato bushy stunt virus particle. The polypeptide chain of each subunit folds into three domains (R, S, P) with a 35-residue connecting arm (a) between R and S and a hinge (h) between S and P.

Figure 16.9 Contacts between P domains in tomato bushy stunt virus. Sa, Sb, and Sc are the shell domains of subunits A, B, and C, respectively. Pa, Pb, and Pc are the protruding domains of subunits A, B, and C, respectively.

Figure 16.13 The known subunit structures of plant. Insect, and animal viruses are of the jelly roll antiparallel p barrel type, described in Chapter 5. This fold, which is schematically illustrated in two different ways, (a) and (b), forms the core of the S domain of the subunit of tomato bushy stunt virus (c). [(b), (c) Adapted from A.J. Olson et al., /. Mol. Biol. 171 61-93, 1983.1...

Tomato bushy stunt virus is a T = 3 plant virus with 180 chemically identical subunits. Each polypeptide chain is divided into several domains. The subunits preserve quasi-equivalent packing in most contact regions by conformational differences of the protein chains, especially a large change in... 

In tomato bushy stunt virus protein, domain hinging helps to solve... 

Fig. 69. The two different positions of the hinge between domains 2 and 3 of tomato bushy stunt virus protein. Each domain is represented by a cylinder, with domain 2 as the reference and domain 3 shown in the relative positions it takes in type B subunits and in type C subunits.

Fig. 70. Domains 2 (cylinders) and N-terminal tails of B- and C-type subunits around the quasi-6-fold axis in tomato bushy stunt virus. The association of the three C-subunit tails around the quasi-6-fold forms domain 1 (see Fig. 84).

Tomato bushy stunt virus protein domains 2 and 3 Southern bean mosaic virus protein Concanavalin A... 

E. Miscellaneous antiparallel /3 Gene 5 protein, E. coli Lactate dehydrogenase domain 2 Tomato bushy stunt virus protein domain 1 IV. Small disulfide-rich or metal-rich domains... 

The remaining three antiparallel /3 structures form a miscellaneous category (see Fig. 84). Lactate dehydrogenase d2 and gene 5 protein each has several two-stranded antiparallel j8 ribbons, but they do not coalesce into any readily described overall pattern. The N-terminal domain of tomato bushy stunt virus protein has a unique /3 structure in which equivalent pieces of chain from three different subunits wrap around a 3-fold axis to form what has been called a /3 annulus (Harrison et ah, 1978). Each of the three chains contributes a short strand segment to each of three three-stranded, interlocking /3 sheets. This domain provides one of the subunit contacts that hold the virus... 

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