Hydroxylation of long chain fatty acids by CYP147F1, a new cytochrome P450 subfamily protein from Streptomyces peucetius

Cytochrome P450 (CYP) 147F1 from Streptomyces peucetius is a new CYP subfamily of that has been identified as ω-fatty acid hydroxylase. We describe the identification of CYP147F1 as a fatty acid hydroxylase by screening for the substrate using a substrate binding assay. Screening of substrates resulted in the identification of fatty acid groups of compounds as potential hits for CYP147F1 substrates. Fatty acids from C_10:0 to C_18:0 all showed type I shift spectra indicating their potential as substrates. Among several fatty acids tested, lauric acid, myrsitic acid, and palmitic acid were used to characterize CYP147F1. CYP147F1 activity was reconstituted using putidaredoxin reductase and putidaredoxin from Pseudomonas putida as surrogate electron transfer partners. Kinetic parameters, including the dissociation constant, K_m, NADH consumption assay, production formation rate, and coupling efficiency for CYP147F1 were also determined.     

Emerging Molecular Strategies for Improving Rice Drought Tolerance

Rice occupies a pre-eminent position as a food crop in the world. Its production, how- ever, entails up to 3000 liters of water per kilogram of grain produced. Such high demand makes rice prone to drought easily. Sustainable rice cultivation with limited water resources requires the deployment of a suitable strategy for better water use efficiency and improved drought tolerance. Several drought-related genes have been evaluated in rice for their mode of action in conferring drought tolerance. Manipulation of components of abscisic acid signal transduction, stomatal density, deposition of cuticular wax, and protein modification pathways are emerging as priority targets. Gene reprogramming by microRNAs is also being explored to achieve drought tolerance. Genetically dissected Quantitative Trait Loci (QTLs) and their constituent genes are being deployed to develop drought-tolerant rice varieties. Progressive research and challenges include a better understanding of crucial components of drought response and search for new targets and the deployment of improved varieties in the field.