Circular dichroism of the parallel beta helical proteins pectate lyase C and E.
The pectate lyases, PelC and PelE, have an unusual folding motif, known as a parallel beta-helix, in which the polypeptide chain is coiled into a larger helix composed of three parallel beta-sheets connected by loops having variable lengths and conformations. Since the regular secondary structure consists almost entirely of parallel beta-sheets these proteins provide a unique opportunity to study the effect of parallel beta-helical structure on circular dichroism (CD). We report here the CD spectra of PelC and PelE in the presence and absence of Ca2+, derive the parallel beta-helical components of the spectra, and compare these results with previous CD studies of parallel beta-sheet structure. The shape and intensity of the parallel beta-sheet spectrum is distinctive and may be useful in identifying other proteins that contain the parallel beta-helical folding motif.
Department of Chemistry and Biochemistry, University of Delaware, Newark 19716, USA.
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Sieber
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Jurnak
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Moe
D001426:Bacterial Proteins; D002118:Calcium / Q000378:metabolism; D002942:Circular Dichroism; D007527:Isoenzymes / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D011133:Polysaccharide-Lyases / Q000737:chemistry* / Q000378:metabolism; D017510:Protein Folding; D017433:Protein Structure, Secondary
D001426:Bacterial Proteins; D007527:Isoenzymes; C097529:PelE protein, Erwinia chrysanthemi; D011133:Polysaccharide-Lyases; C023911:pectate lyase; D002118:Calcium