5MQZ

Archaeal branched-chain amino acid aminotransferase from Archaeoglobus fulgidus; holoform

Summary for 5MQZ

• Entry DOI: 10.2210/pdb5mqz/pdb
• Descriptor: Putative branched-chain-amino-acid aminotransferase, CHLORIDE ION, DI(HYDROXYETHYL)ETHER, ... (6 entities in total)
• Functional Keywords: branch-chain transaminase, thermophilic archaea, substrate specificity, transferase
• Biological source: Archaeoglobus fulgidus (strain ATCC 49558 / VC-16 / DSM 4304 / JCM 9628 / NBRC 100126)
• Total number of polymer chains: 6
• Total formula weight: 196618.02

Authors

James, P.,Isupov, M.N.,Sayer, C.,Littlechild, J.A.,Sutter, J.M.,Schmidt, M.,Schoenheit, P. (deposition date: 2016-12-21, release date: 2018-01-17, Last modification date: 2024-01-17)

Primary citation

Isupov, M.N.,Boyko, K.M.,Sutter, J.M.,James, P.,Sayer, C.,Schmidt, M.,Schonheit, P.,Nikolaeva, A.Y.,Stekhanova, T.N.,Mardanov, A.V.,Ravin, N.V.,Bezsudnova, E.Y.,Popov, V.O.,Littlechild, J.A.
Thermostable Branched-Chain Amino Acid Transaminases From the Archaea Geoglobus acetivorans and Archaeoglobus fulgidus : Biochemical and Structural Characterization.
Front Bioeng Biotechnol, 7:7-7, 2019

PubMed Abstract: Two new thermophilic branched chain amino acid transaminases have been identified within the genomes of different hyper-thermophilic archaea, , and . These enzymes belong to the class IV of transaminases as defined by their structural fold. The enzymes have been cloned and over-expressed in and the recombinant enzymes have been characterized both biochemically and structurally. Both enzymes showed high thermostability with optimal temperature for activity at 80 and 85°C, respectively. They retain good activity after exposure to 50% of the organic solvents, ethanol, methanol, DMSO and acetonitrile. The enzymes show a low activity to ()-methylbenzylamine but no activity to ()-methylbenzylamine. Both enzymes have been crystallized and their structures solved in the internal aldimine form, to 1.9 Å resolution for the enzyme and 2.0 Å for the enzyme. Also the enzyme structure has been determined in complex with the amino acceptor α-ketoglutarate and the enzyme in complex with the inhibitor gabaculine. These two complexes have helped to determine the conformation of the enzymes during enzymatic turnover and have increased understanding of their substrate specificity. A comparison has been made with another () selective class IV transaminase from the fungus which was previously studied in complex with gabaculine. The subtle structural differences between these enzymes has provided insight regarding their different substrate specificities.

PubMed: 30733943
DOI: 10.3389/fbioe.2019.00007

Experimental method

X-RAY DIFFRACTION (2.1 Å)