Ironing out their differences: dissecting the structural determinants of a phenylalanine aminomutase and ammonia lyase
| Autor: | Dick B. Janssen, Marcelo F. Masman, Sebastian Bartsch, Bauke W. Dijkstra, Siewert J. Marrink, Matthew M. Heberling, Gjalt G. Wybenga |
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| Přispěvatelé: | Biotechnology, X-ray Crystallography, Molecular Dynamics |
| Rok vydání: | 2014 |
| Předmět: |
Models
Molecular Ammonia-Lyases ORGANIC-SOLVENTS Stereochemistry Protein Conformation COSOLVENT MIXTURES Phenylalanine Phenylalanine ammonia-lyase Molecular Dynamics Simulation Crystallography X-Ray Biochemistry Residue (chemistry) LACCASE stomatognathic system Catalytic Domain parasitic diseases MUTATIONAL ANALYSIS CATALYTIC-ACTIVITY BETA-AMINO ACIDS Intramolecular Transferases Inner loop Phenylalanine Ammonia-Lyase chemistry.chemical_classification Chemistry Temperature General Medicine Lyase FAMILY Amino acid Enzyme Molecular Medicine ENZYMES |
| Zdroj: | ACS chemical biology, 10(4), 989-997. AMER CHEMICAL SOC |
| ISSN: | 1554-8937 1554-8929 |
| Popis: | Deciphering the structural features that functionally separate ammonia lyases from aminomutases is of interest because it may allow for the engineering of more efficient aminomutases for the synthesis of unnatural amino acids (e.g., beta-amino acids). However, this has proved to be a major challenge that involves understanding the factors that influence their activity and regioselectivity differences. Herein, we report evidence of a structural determinant that dictates the activity differences between a phenylalanine ammonia lyase (PAL) and aminomutase (PAM). An inner loop region that closes the active sites of both PAM and PAL was mutated within PAM (PAM residues 77-97) in a stepwise approach to study the effects when the equivalent residue(s) found in the PAL loop were introduced into the PAM loop. Almost all of the single loop mutations triggered a lyase phenotype in PAM. Experimental and computational evidence suggest that the induced lyase features result from inner loop mobility enhancements, which are possibly caused by a 3(10)-helix cluster, flanking a-helices, and hydrophobic interactions. These findings pinpoint the inner loop as a structural determinant of the lyase and mutase activities of PAM. |
| Databáze: | OpenAIRE |
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