8ISC

Crystal structure of MV in complex with LLP

Summary for 8ISC

• Entry DOI: 10.2210/pdb8isc/pdb
• Descriptor: Branched chain amino acid: 2-keto-4-methylthiobutyrate aminotransferase (2 entities in total)
• Functional Keywords: complex, transferase
• Biological source: Mycolicibacterium vanbaalenii (strain DSM 7251 / JCM 13017 / BCRC 16820 / KCTC 9966 / NRRL B-24157 / PYR-1) (Mycobacterium vanbaalenii)
• Total number of polymer chains: 4
• Total formula weight: 147529.41

Authors

Li, Q.,Zhu, Y.M.,Gao, J.,Wei, H.L.,Han, X.,Liu, W.D.,Sun, Y.X. (deposition date: 2023-03-20, release date: 2024-01-24, Last modification date: 2025-08-06)

Primary citation

Zhu, Y.,Chen, P.,Dong, Q.,Li, Q.,Liu, D.,Liu, T.,Liu, W.,Sun, Y.
Protein engineering of transaminase facilitating enzyme cascade reaction for the biosynthesis of azasugars.
Iscience, 27:109034-109034, 2024

PubMed Abstract: Azasugars, such as 1-deoxynojirimycin (1-DNJ), exhibit unique physiological functions and hold promising applications in medicine and health fields. However, the biosynthesis of 1-DNJ is hindered by the low activity and thermostability of the transaminase. In this study, the transaminase from (MvTA) with activity toward d-fructose was engineered through semi-rational design and high-throughput screening method. The final mutant M9-1 demonstrated a remarkable 31.2-fold increase in specific activity and an impressive 200-fold improvement in thermostability compared to the wild-type enzyme. Molecular dynamics (MD) simulations revealed that the mutation sites of H69R and K145R in M9-1 played crucial roles in the binding of the amino acceptor and donor, leading to the stable conformation of substrates within the active pocket. An enzyme cascade reaction was developed using M9-1 and the dehydrogenase from (GutB1) for the production of mannojirimycin (MJ), which provided a new idea for the biosynthesis of 1-DNJ.

PubMed: 38433920
DOI: 10.1016/j.isci.2024.109034

Experimental method

X-RAY DIFFRACTION (2.27 Å)