Functional annotation of an ecologically important protein from Chloroflexus aurantiacus involved in polyhydroxyalkanoates (PHA) biosynthetic pathway

Abstract

Chloroflexus aurantiacus J-10-fI strain is a thermophilic gram-negative bacterium that possesses many proteins in its genome; some are considered as hypothetical proteins. The use of bioinformatics tools can assist in understanding this organism through structural and functional annotation. Our study aimed to assign structure and function to an ecologically important hypothetical protein present in the bacterial genome. To analyze the hypothetical protein (WP_012259469.1), we used an in silico approach to find out various properties like physiochemical characteristics, subcellular localization, 3D structure, protein–protein interaction and functional annotation. Protein–protein interactions were obtained from the STRING database. In silico analysis revealed that the protein is a soluble protein with predominantly alpha-helices in its secondary structure. The 3D model of the protein has been found to be novel and possessed expected quality as assessed by several quality assessment tools. Functional annotation indicated that the protein acted like a (R)-specific enoyl-CoA hydratase which is linked with PHA synthesis. Protein–protein interactions also showed with high confidence that the protein interacted with a protein synthesizer of enoyl-CoA hydratase involved in PHA biosynthesis. Polyhydroxyalkanoate (PHA) is a novel polyester used as a biodegradable thermoplastic and plays a crucial role in environmental biodegradability and biocompatibility. An extensive variety of microorganisms produces PHA for intracellular carbon and energy storage purposes. In the present investigation, we bioinformatically confirmed that the WP_012259469.1 is associated with the PHA biosynthesis pathway. From our anaylses, we also predict that polyhydroxyalkanoate (PHAs) has the potential to become an alternative source of renewable and biodegradable polyesters.