A microbial platform for renewable propane synthesis based on a fermentative butanol pathway.

Background: Propane (C3H8) is a volatile hydrocarbon with highly favourable physicochemical properties as a fuel, in addition to existing global markets and infrastructure for storage, distribution and utilization in a wide range of applications. Consequently, propane is an attractive target product in research aimed at developing new renewable alternatives to complement currently used petroleum-derived fuels. This study focuses on the construction and evaluation of alternative microbial biosynthetic pathways for the production of renewable propane.

Glutamate 338 is an electrostatic facilitator of C-Co bond breakage in a dynamic/electrostatic model of catalysis by ornithine aminomutase.

How cobalamin-dependent enzymes promote C-Co homolysis to initiate radical catalysis has been debated extensively. For the pyridoxal 5'-phosphate and cobalamin-dependent enzymes lysine 5,6-aminomutase and ornithine 4,5-aminomutase (OAM), large-scale re-orientation of the cobalamin-binding domain linked to C-Co bond breakage has been proposed. In these models, substrate binding triggers dynamic sampling of the B12 -binding Rossmann domain to achieve a catalytically competent 'closed' conformational state.

Production of propane and other short-chain alkanes by structure-based engineering of ligand specificity in aldehyde-deformylating oxygenase.

Biocatalytic propane production: structure-based engineering of aldehyde-deformylating oxygenase improves specificity for short- and medium-chain-length aldehydes and enhances the propane generation in whole-cell biotransformations. This presents new opportunities for developing biocatalytic modules for the production of volatile "drop-in" biofuels.