Crystal Structure of Allantoinase from Escherichia coli BL21: A Molecular Insight into a Role of the Active Site Loops in Catalysis

Autor: Yen-Hua Huang, Po-Chun Yang, En-Shyh Lin, Ya-Yeh Ho, Wei-Feng Peng, Hsin-Pin Lu, Chien-Chih Huang, Cheng-Yang Huang
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: Molecules, Vol 28, Iss 2, p 827 (2023)
Druh dokumentu: article
ISSN: 1420-3049
DOI: 10.3390/molecules28020827
Popis: Allantoinase (ALLase; EC 3.5.2.5) possesses a binuclear metal center in which two metal ions are bridged by a posttranslationally carbamylated lysine. ALLase acts as a key enzyme for the biogenesis and degradation of ureides by catalyzing the conversion of allantoin into allantoate. Biochemically, ALLase belongs to the cyclic amidohydrolase family, which also includes dihydropyrimidinase, dihydroorotase, hydantoinase (HYDase), and imidase. Previously, the crystal structure of ALLase from Escherichia coli K-12 (EcALLase-K12) was reported; however, the two active site loops crucial for substrate binding were not determined. This situation would limit further docking and protein engineering experiments. Here, we solved the crystal structure of E. coli BL21 ALLase (EcALLase-BL21) at a resolution of 2.07 Å (PDB ID 8HFD) to obtain more information for structural analyses. The structure has a classic TIM barrel fold. As compared with the previous work, the two missed active site loops in EcALLase-K12 were clearly determined in our structure of EcALLase-BL21. EcALLase-BL21 shared active site similarity with HYDase, an important biocatalyst for industrial production of semisynthetic penicillin and cephalosporins. Based on this structural comparison, we discussed the functional role of the two active site loops in EcALLase-BL21 to better understand the substrate/inhibitor binding mechanism for further biotechnological and pharmaceutical applications.
Databáze: Directory of Open Access Journals
Nepřihlášeným uživatelům se plný text nezobrazuje