A novel secondary structure based on fused five-membered rings motif.

Dhar, Jesmita and Kishore, Raghuvansh and Chakrabarti, Pinak (2016) A novel secondary structure based on fused five-membered rings motif. Scientific reports, 6. p. 31483. ISSN 2045-2322

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Abstract

An analysis of protein structures indicates the existence of a novel, fused five-membered rings motif, comprising of two residues (i and i + 1), stabilized by interresidue Ni+1-H∙∙∙Ni and intraresidue Ni+1-H∙∙∙O=Ci+1 hydrogen bonds. Fused-rings geometry is the common thread running through many commonly occurring motifs, such as β-turn, β-bulge, Asx-turn, Ser/Thr-turn, Schellman motif, and points to its structural robustness. A location close to the beginning of a β-strand is rather common for the motif. Devoid of side chain, Gly seems to be a key player in this motif, occurring at i, for which the backbone torsion angles cluster at ~(-90°, -10°) and (70°, 20°). The fused-rings structures, distant from each other in sequence, can hydrogen bond with each other, and the two segments aligned to each other in a parallel fashion, give rise to a novel secondary structure, topi, which is quite common in proteins, distinct from two major secondary structures, α-helix and β-sheet. Majority of the peptide segments making topi are identified as aggregation-prone and the residues tend to be conserved among homologous proteins.

Item Type:	Article
Additional Information:	Open Access
Uncontrolled Keywords:	Protein Analysis; Structure biology
Subjects:	Q Science > QR Microbiology
Depositing User:	Dr. K.P.S.Sengar
Date Deposited:	29 Sep 2016 10:51
Last Modified:	29 Sep 2016 10:51
URI:	http://crdd.osdd.net/open/id/eprint/1864

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