Crystal Structure of Allantoinase from <i>Escherichia coli</i> BL21: A Molecular Insight into a Role of the Active Site Loops in Catalysis oleh Yen-Hua Huang, Po-Chun Yang, En-Shyh Lin, Ya-Yeh Ho, Wei-Feng Peng, Hsin-Pin Lu, Chien-Chih Huang, Cheng-Yang Huang