Busch Florian, Rajendran Chitra, Mayans Olga, Löffler Patrick, Merkl Rainer, Sterner Reinhard
Institute of Biophysics and Physical Biochemistry, University of Regensburg , Universitätsstrasse 31, D-93053 Regensburg, Germany.
Biochemistry. 2014 Sep 30;53(38):6078-83. doi: 10.1021/bi500977y. Epub 2014 Sep 17.
The rapid increase of the number of sequenced genomes asks for the functional annotation of the encoded enzymes. We used a combined computational-structural approach to determine the function of the TrpB2 subgroup of the tryptophan synthase β chain/β chain-like TrpB1-TrpB2 family (IPR023026). The results showed that TrpB2 enzymes are O-phospho-l-serine dependent tryptophan synthases, whereas TrpB1 enzymes catalyze the l-serine dependent synthesis of tryptophan. We found a single residue being responsible for the different substrate specificities of TrpB1 and TrpB2 and confirmed this finding by mutagenesis studies and crystallographic analysis of a TrpB2 enzyme with bound O-phospho-l-serine.
已测序基因组数量的迅速增加要求对编码的酶进行功能注释。我们采用了一种计算结构相结合的方法来确定色氨酸合酶β链/类β链TrpB1-TrpB2家族（IPR023026）中TrpB2亚组的功能。结果表明，TrpB2酶是O-磷酸-L-丝氨酸依赖性色氨酸合酶，而TrpB1酶催化L-丝氨酸依赖性色氨酸的合成。我们发现一个单一残基负责TrpB1和TrpB2不同的底物特异性，并通过诱变研究和结合O-磷酸-L-丝氨酸的TrpB2酶的晶体学分析证实了这一发现。
