Publication Abstract from PubMed
Though the three-dimensional structures of barley alpha-amylase isozymes AMY1 and AMY2 are very similar, they differ remarkably from each other in their affinity for Ca(2+) and when interacting with substrate analogs. A surface site recognizing maltooligosaccharides, not earlier reported for other alpha-amylases and probably associated with the different activity of AMY1 and AMY2 toward starch granules, has been identified. It is located in the C-terminal part of the enzyme and, thus, highlights a potential role of domain C. In order to scrutinize the possible biological significance of this domain in alpha-amylases, a thorough comparison of their three-dimensional structures was conducted. An additional role for an earlier-identified starch granule binding surface site is proposed, and a new calcium ion is reported.
The structure of barley alpha-amylase isozyme 1 reveals a novel role of domain C in substrate recognition and binding: a pair of sugar tongs.,Robert X, Haser R, Gottschalk TE, Ratajczak F, Driguez H, Svensson B, Aghajari N Structure. 2003 Aug;11(8):973-84. PMID:12906828[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
