Illuminating structure and acyl donor sites of a physiological transglutaminase substrate from Streptomyces mobaraensis.

ABSTRACT: Transglutaminase from Streptomyces mobaraensis (MTG) has become a powerful tool to covalently and highly specifically link functional amines to glutamine donor sites of therapeutic proteins. However, details regarding the mechanism of substrate recognition and interaction of the enzyme with proteinaceous substrates still remain mostly elusive. We have determined the crystal structure of the Streptomyces papain inhibitory protein (SPI_p ), a substrate of MTG, to study the influence of various substrate amino acids on positioning glutamine to the active site of MTG. SPI_p exhibits a rigid, thermo-resistant double-psi-beta-barrel fold that is stabilized by two cysteine bridges. Incorporation of biotin cadaverine identified Gln-6 as the only amine acceptor site on SPI_p

SUBMITTER: Juettner NE 

PROVIDER: S-EPMC5916126 | biostudies-literature | 2018 May

REPOSITORIES: biostudies-literature