Multiple novel membrane proteins involve phthalate ester degradation in Rhodococcus sp. AH-ZY2

Area of Science:

• Environmental microbiology
• Biochemistry
• Molecular biology

Background:

• Phthalate esters (PAEs) are widespread environmental pollutants with significant toxicity.
• Microbial degradation is a key strategy for PAE bioremediation, but transport mechanisms are poorly understood.
• Membrane proteins play a crucial role in facilitating the uptake of PAEs for microbial degradation.

Purpose of the Study:

• To identify and characterize novel membrane proteins involved in the transport of phthalate esters (PAEs) in Rhodococcus sp. AH-ZY2.
• To elucidate the role of these transport proteins in PAE degradation and explore their potential for bioremediation.
• To investigate the molecular mechanisms underlying PAE transport by these membrane proteins.

Main Methods:

• Whole-genome and transcriptomic analyses to predict potential PAE transport proteins.
• Gene knockout and complementation experiments for functional verification.
• Molecular docking simulations to analyze protein-substrate interactions.
• Gene cloning and expression enhancement in Rhodococcus sp. AH-ZY2.

Main Results:

• Four novel membrane protein genes (0620, 3572, 4497, and 5299) were identified and functionally verified for PAE transport.
• Proteins 0620, 3572, and 5299 belong to the MFS family, while 4497 belongs to the ABC family.
• Membrane protein 5299 demonstrated the broadest substrate range for PAE transport, with specific amino acid residues (Ser, Arg) crucial for binding.
• Enhanced expression of these genes, especially 5299, significantly improved PAE degradation efficiency.

Conclusions:

• Four novel membrane transport proteins were identified, highlighting their critical role in microbial PAE degradation.
• The study provides a new strategy for enhancing PAE bioremediation through the engineering of membrane transport.
• These findings contribute to a deeper understanding of PAE uptake mechanisms and offer potential for developing more effective bioremediation technologies.