Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Bernal, Argentina.
Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), CABA, Argentina.
Protein Sci. 2024 Apr;33(4):e4935. doi: 10.1002/pro.4935.
Flavin-dependent monooxygenases (FMOs) constitute a diverse enzyme family that catalyzes crucial hydroxylation, epoxidation, and Baeyer-Villiger reactions across various metabolic pathways in all domains of life. Due to the intricate nature of this enzyme family's mechanisms, some aspects of their functioning remain unknown. Here, we present the results of molecular dynamics computations, supplemented by a bioinformatics analysis, that clarify the early stages of their catalytic cycle. We have elucidated the intricate binding mechanism of NADPH and L-Orn to a class B monooxygenase, the ornithine hydroxylase from known as SidA. Our investigation involved a comprehensive characterization of the conformational changes associated with the FAD (Flavin Adenine Dinucleotide) cofactor, transitioning from the out to the in position. Furthermore, we explored the rotational dynamics of the nicotinamide ring of NADPH, shedding light on its role in facilitating FAD reduction, supported by experimental evidence. Finally, we also analyzed the extent of conservation of two Tyr-loops that play critical roles in the process.
黄素依赖单加氧酶（FMOs）构成了一个多样化的酶家族，在所有生命领域的各种代谢途径中，催化关键的羟化、环氧化和 Baeyer-Villiger 反应。由于该酶家族的机制非常复杂，其功能的某些方面仍然未知。在这里，我们展示了分子动力学计算的结果，并辅以生物信息学分析，阐明了它们催化循环的早期阶段。我们阐明了 NADPH 和 L-Orn 与 B 类单加氧酶结合的复杂机制，该酶是SidA 中已知的鸟氨酸羟化酶。我们的研究涉及到与黄素腺嘌呤二核苷酸（FAD）辅因子相关的构象变化的全面特征化，从外到内位置的转变。此外，我们还探索了 NADPH 的烟酰胺环的旋转动力学，实验证据支持其在促进 FAD 还原中的作用。最后，我们还分析了在该过程中起关键作用的两个 Tyr 环的保守程度。
