Klebsiella pneumoniae pullulanase (KPP) belongs to glycoside hydrolase family 13 subfamily 13 (GH13_13) and is the only enzyme that is reported to perform an induced‐fit motion of the active‐site loop (residues 706–710). Comparison of pullulanase structures indicated that only KPP has Leu680 present behind the loop, in contrast to the glycine found in other GH13_13 members. Analysis of the structure and activity of recombinant pullulanase from K. pneumoniae ATCC 9621 (rKPP) and its mutant (rKPP‐G680L) indicated that the side chain of residue 680 is important for the induced‐fit motion of the loop 706–710 and alters the binding affinity of the substrate.

中文翻译：

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诱导拟合环与肺炎克雷伯菌支链淀粉酶活性之间的关系。

肺炎克雷伯氏菌支链淀粉酶（KPP）属于糖苷水解酶家族13亚家族13（GH13_13），并且是唯一据报道对活性位点环执行诱导拟合运动的酶（残基706-710）。支链淀粉酶结构的比较表明，与其他GH13_13成员中的甘氨酸相反，只有KPP的Leu680存在于环的后面。对来自肺炎克雷伯菌ATCC 9621（rKPP）及其突变体（rKPP-G680L）的重组支链淀粉酶的结构和活性的分析表明，残基680的侧链对于环706-710的诱导拟合运动和改变很重要。底物的结合亲和力。