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The β1 domain of protein G can replace the chorismate mutase domain of the T‐protein
Author(s) -
Osuna Joel,
Flores Humberto,
Saab-Rincón Gloria
Publication year - 2012
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2012.01.033
Subject(s) - chorismate mutase , context (archaeology) , domain (mathematical analysis) , c terminus , protein domain , biology , fusion protein , stereochemistry , protein structure , biochemistry , amino acid , chemistry , recombinant dna , gene , phenylalanine , paleontology , mathematical analysis , mathematics
T‐protein is composed of chorismate mutase (AroQ T ) fused to the N‐terminus of prephenate dehydrogenase (TyrA). Here, we report the replacement of AroQ T with the β1‐domain of protein G (Gβ1). The TyrA domain shows a strong dehydrogenase activity within the context of this fusion, and our data indicate that Gβ1‐TyrA folds into a dimeric conformation. Amino acid substitutions in the Gβ1 domain of Gβ1‐TyrA identified residues involved in stabilizing the TyrA dimeric conformation. Gβ1 substitutions in the N‐terminal β‐hairpin eliminated Gβ1‐TyrA expression, whereas Gβ1‐TyrA tolerated Gβ1 substitutions in the C‐terminal β‐hairpin and in the α‐helix. All of the characterized variants folded into a dimeric conformation. The importance of the β2‐strand in forming a Gβ1 homo‐dimerization interface explains the relevance of the first‐β‐hairpin in stabilizing the dimeric TyrA protein.