Lee S H, Taguchi H, Yoshimura E, Minagawa E, Kaminogawa S, Ohta T, Matsuzawa H
Department of Agricultural Chemistry, Japan.
Protein Eng. 1996 Jun;9(6):467-9. doi: 10.1093/protein/9.6.467.
Carboxypeptidase (CPase) Taq possesses the His-Glu-X-X-His sequence, which is the consensus sequence in the active site of zinc-dependent endopeptidases and amino-peptidases, at positions 276-280. Amino acid replacement of the conserved His and Glu drastically diminished the activity of CPase Taq, and the zinc content of the enzyme was also greatly reduced when either of the two His residues was replaced with Arg or Tyr. The results indicate that this sequence actually functions as the active site in CPase Taq, showing that CPase Taq is a novel type of zinc-dependent CPase that possesses the His-Glu-X-X-His active-site motif.
羧肽酶（CPase）Taq在276 - 280位具有His-Glu-X-X-His序列，这是锌依赖性内肽酶和氨肽酶活性位点的共有序列。保守的His和Glu的氨基酸替换极大地降低了CPase Taq的活性，并且当两个His残基中的任何一个被Arg或Tyr取代时，该酶的锌含量也大大降低。结果表明，该序列实际上作为CPase Taq的活性位点发挥作用，表明CPase Taq是一种新型的具有His-Glu-X-X-His活性位点基序的锌依赖性羧肽酶。
