5OT0

The thermostable L-asparaginase from Thermococcus kodakarensis

Summary for 5OT0

• Entry DOI: 10.2210/pdb5ot0/pdb
• Descriptor: L-asparaginase, PHOSPHATE ION, 1,2-ETHANEDIOL, ... (5 entities in total)
• Functional Keywords: thermostable, homodimer, leukaemia, hydrolase
• Biological source: Thermococcus kodakarensis (strain ATCC BAA-918 / JCM 12380 / KOD1)
• Total number of polymer chains: 6
• Total formula weight: 215432.44

Authors

Guo, J.,Coker, A.R.,Wood, S.P.,Cooper, J.B.,Rashid, N.,Chohan, S.M.,Akhtar, M. (deposition date: 2017-08-18, release date: 2017-11-08, Last modification date: 2024-01-17)

Primary citation

Guo, J.,Coker, A.R.,Wood, S.P.,Cooper, J.B.,Chohan, S.M.,Rashid, N.,Akhtar, M.
Structure and function of the thermostable L-asparaginase from Thermococcus kodakarensis.
Acta Crystallogr D Struct Biol, 73:889-895, 2017

PubMed Abstract: L-Asparaginases catalyse the hydrolysis of asparagine to aspartic acid and ammonia. In addition, L-asparaginase is involved in the biosynthesis of amino acids such as lysine, methionine and threonine. These enzymes have been used as chemotherapeutic agents for the treatment of acute lymphoblastic leukaemia and other haematopoietic malignancies since the tumour cells cannot synthesize sufficient L-asparagine and are thus killed by deprivation of this amino acid. L-Asparaginases are also used in the food industry and have potential in the development of biosensors, for example for asparagine levels in leukaemia. The thermostable type I L-asparaginase from Thermococcus kodakarensis (TkA) is composed of 328 amino acids and forms homodimers in solution, with the highest catalytic activity being observed at pH 9.5 and 85°C. It has a K value of 5.5 mM for L-asparagine, with no glutaminase activity being observed. The crystal structure of TkA has been determined at 2.18 Å resolution, confirming the presence of two α/β domains connected by a short linker region. The N-terminal domain contains a highly flexible β-hairpin which adopts `open' and `closed' conformations in different subunits of the solved TkA structure. In previously solved L-asparaginase structures this β-hairpin was only visible when in the `closed' conformation, whilst it is characterized with good electron density in all of the subunits of the TkA structure. A phosphate anion resides at the active site, which is formed by residues from both of the neighbouring monomers in the dimer. The high thermostability of TkA is attributed to the high arginine and salt-bridge content when compared with related mesophilic enzymes.

PubMed: 29095161
DOI: 10.1107/S2059798317014711

Experimental method

X-RAY DIFFRACTION (2.18 Å)