9THY
ReAIV structure containing an acrylamide adduct at Cys183 and an orthoborate ester at Ser47
Summary for 9THY
| Entry DOI | 10.2210/pdb9thy/pdb |
| Related | 8OSW |
| Descriptor | L-asparaginase II protein, ZINC ION, CHLORIDE ION, ... (7 entities in total) |
| Functional Keywords | l-asparaginase, acrylamide, zinc metalloenzyme, adduct, microcalorimetry, itc, hydrolase |
| Biological source | Rhizobium etli More |
| Total number of polymer chains | 2 |
| Total formula weight | 73372.67 |
| Authors | Sliwiak, J.,Grzechowiak, M.,Worsztynowicz, P.,Pokrywka, K.,Ruszkowski, M.,Gilski, M.,Jaskolski, M. (deposition date: 2025-12-04, release date: 2026-05-27) |
| Primary citation | Sliwiak, J.,Grzechowiak, M.,Worsztynowicz, P.,Pokrywka, K.,Ruszkowski, M.,Gilski, M.,Jaskolski, M. Efficient acrylamide adduct formation suggests dual applications of ReAIV L-asparaginase. Amino Acids, 2026 Cited by PubMed Abstract: Isothermal titration calorimetry (ITC) studies of the enzyme kinetics and substrate specificity of Rhizobium etli Class 3 L-asparaginases, ReAIV (constitutive) and ReAV (inducible), showed that despite highly conserved catalytic site, the two isoforms differ significantly in thermostability, zinc affinity, and biochemical properties. As part of a wider investigation of potential non-natural substrates, acrylamide was tested, revealing a pronounced heat effect with ReAIV but none with ReAV. Crystallographic analysis showed the formation of a Michael adduct between acrylamide and a surface-exposed cysteine 183 in ReAIV, while the catalytic activity toward L-asparagine hydrolysis remained unaffected. These findings highlight the unique and multimodal reactivity of ReAIV, suggesting its potential dual application in the food industry: in selective removal of L-asparagine and in covalent sequestration of acrylamide under mild conditions. The acrylamide modification improved crystal morphology of ReAIV, offering practical advantages for structural studies. Additionally, a covalent modification of the catalytic Ser47 residue was observed in the presented crystal structure. Based on B-factor analysis, literature data, and detection of borate contamination in the laboratory water, this modification was interpreted as an orthoborate ester. PubMed: 42113412DOI: 10.1007/s00726-026-03525-1 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.4 Å) |
Structure validation
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