Statistical Analysis of Terminal Extensions of Proteinβ-Strand Pairs

[摘要] The long-range interactions, required to the accurate predictions of tertiary structures ofβ-sheet-containing proteins, are still difficult to simulate. To remedy this problem and to facilitateβ-sheet structure predictions, many efforts have been made by computational methods. However, known efforts onβ-sheets mainly focus on interresidue contacts or amino acid partners. In this study, to go one step further, we studiedβ-sheets on the strand level, in which a statistical analysis was made on the terminal extensions of pairedβ-strands. In most cases, the two pairedβ-strands have different lengths, and terminal extensions exist. The terminal extensions are the extended part of the paired strands besides the common paired part. However, we found that the best pairing required a terminal alignment, andβ-strands tend to pair to make bigger common parts. As a result, 96.97%  ofβ-strand pairs have a ratio of 25% of the paired common part to the whole length. Also 94.26% and 95.98%  ofβ-strand pairs have a ratio of 40% of the paired common part to the length of the twoβ-strands, respectively. Interstrand register predictions by searching interactingβ-strands from several alternative offsets should comply with this rule to reduce the computational searching space to improve the performances of algorithms.

[学科分类] 生物技术