Jelly-roll motif

The jelly roll motif is wrapped around a barrel... 

To illustrate how this rather complicated structure is built up, we will start by wrapping a piece of string around a barrel as shown in Figure S.16. The string goes up and down the barrel four times, crosses over once at the bottom and twice at the top of the barrel. This configuration is the basic pattern for the jelly roll motif. 

Figure S.16 A diagram of a piece of string wrapped around a barrel to illustrate the basic pattern of a jelly roll motif.

We have already discussed one envelope protein of influenza virus, neuraminidase, as an example of an up-and-down antiparallel p motif. In the second envelope protein, hemagglutinin, one domain of the polypeptide chain is folded into a jelly roll motif. We shall now look at some other features of hemagglutinin that are important for its biological function. 

Figure 5.23 The globular head of the hemagglutinin subunit Is a distorted jelly roll stmcture (a). P strand 1 contains a long Insertion, and P strand 8 contains a bulge in the corresponding position. Each of these two strands is therefore subdivided Into shorter P strands. The loop region between P strands 3 and 4 contains a short a helix, which forms one side of the receptor binding site (yellow circle). A schematic diagram (b) Illustrates the organization of the p strands into a jelly roll motif.

Since the first crystal structure of IPNS (108), which is an enzyme closely related to the Fe/20G-dependent oxygenases, stractures have been determined for many Fe(II)-/20G-dependent oxygenases, all revealing a consensus core double-stranded P-helix (DSBH) fold or jelly-roll motif (66, 102). Typically this core consists of two four-stranded antiparallel P-sheets, with the major sheet supported by closely packed a-helices. The DSBH core is stabilized even more by internal hydrophobic interactions. The active site and HXD/E... H iron binding motif reside within this core stmcture. Additional or varying stmctural features from the DSBH domain define different structural subfamilies of this class of enzyme (66). 

FIGURE 12,38. Motifs in protein architecture, (a) Up-and-down barrel, (b) jelly-roll motif, and (c) (/lajg barrel. Compare these with (d), (e), and (f), which is what the folding looks like in three dimensions. 

Jelly-roll motif The folding of a protein in a manner reminiscent of the fold of a jelly roll. 

A number of protein crystal structures has been obtained for this class of enzymes, including those of isopenicillin-N-synthase, " deacetoxycephalosporin C synthase (DAOCS) Figure 14, and clavaminate synthase (CAS) these structures are currently being studied with regards to the effect of structure on the regioselectivity exhibited by these enzymes. For DAOCS the structure shows a jelly-roll motif with the active site situated in a shallow pocket on the edge of... 

Sattelite Tobacco necrosis virus Jelly roll motif (2STV)... 

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