Genomics-Based Insights Into the Biosynthesis and Unusually High Accumulation of Free Fatty Acids by Streptomyces sp NP10

Schneider O, Ilic-Tomic T, Rückert C, et al. Genomics-Based Insights Into the Biosynthesis and Unusually High Accumulation of Free Fatty Acids by Streptomyces sp NP10. FRONTIERS IN MICROBIOLOGY. 2018;9: 10.Streptomyces sp. NP10 was previously shown to synthesize large amounts of free fatty acids (FFAs). In this work, we report the first insights into the biosynthesis of these fatty acids (FAs) gained after genome sequencing and identification of the genes involved. Analysis of the Streptomyces sp. NP10 draft genome revealed that it is closely related to several strains of Streptomyces griseus. Comparative analyses of secondary metabolite biosynthetic gene clusters, as well as those presumably involved in FA biosynthesis, allowed identification of an unusual cluster C12-2, which could be identified in only one other S. griseus-related streptomycete. To prove the involvement of identified cluster in FFA biosynthesis, one of its three ketosynthase genes was insertionally inactivated to generate mutant strain mNP10. Accumulation of FFAs in mNP10 was almost completely abolished, reaching less than 0.01% compared to the wild-type strain. Cloning and transfer of the C12-2 cluster to the mNP10 mutant partially restored FFA production, albeit to a low level. The discovery of this rare FFA biosynthesis cluster opens possibilities for detailed characterization of the roles of individual genes and their products in the biosynthesis of FFAs in NP10

Mutation of the proteolipid protein gene PLP in a human X chromosome-linked myelin disorder.

Myelin is a highly specialized membrane unique to the nervous system that ensheaths axons to permit the rapid saltatory conduction of impulses. The elaboration of a compact myelin sheath is disrupted in a diverse spectrum of human disorders, many of which are of unknown etiology. The X chromosome-linked human disorder Pelizaeus-Merzbacher disease is a clinically and pathologically heterogeneous group of disorders that demonstrate a striking failure of oligodendrocyte differentiation. This disease appears pathologically and genetically to be similar to the disorder seen in the dysmyelinating mouse mutant jimpy, which has a point mutation in the gene encoding an abundant myelin protein, proteolipid protein (PLP). We report that the molecular defect in one Pelizaeus-Merzbacher family is likewise a point mutation in the PLP gene. A single T----C transition results in the substitution of a charged amino acid residue, arginine, for tryptophan in one of the four extremely hydrophobic domains of the PLP protein. The identification of a mutation in this Pelizaeus-Merzbacher family should facilitate the molecular classification and diagnosis of these X chromosome-linked human dysmyelinating disorders

Evaluation of psychoactive substance use disorder treatment, workbook 6: client satisfaction evaluations.

What is a client satisfaction evaluation? p.7 Why do a client satisfaction evaluation? p.7 How to do a client satisfaction evaluation? p.8 Conclusion and practical recommendation p.17 Comments about case examples p.19 Case examples of client satisfaction evaluation Part A: An evaluation of satisfaction with a state drinker driver treatment program p.21 Part B: Client satisfaction with residential substance treatment programmes p.26 Part C: The case of community methadone treatment programs p.3

A novel mutation in the proteolipid protein gene leading to Pelizaeus-Merzbacher disease.

Point mutations of the gene of human proteolipid protein (PLP) have been recognized as the molecular basis of one form of leukodystrophy, the X-chromosome-linked Pelizaeus-Merzbacher disease (PMD). We report the molecular analysis of four PMD patients in three unrelated families and describe a point mutation (G-->A transition) in exon V which leads to the substitution of Gly216 by a serine residue in a highly conserved extracytosolic domain and a Mae I RFLP. Molecular modelling with energy minimization indicates that this seemingly minor alteration of the amino-acid sequence induces a considerable conformational change and tight packing of the polypeptide chain apparently not compatible with the regular PLP function in oligodendrocytes. This mutation has been detected and characterized by PCR amplification of genomic DNA using intron and exon primers and the complete sequence analysis of the seven exons and a 300 bp promoter region of the PLP gene of two affected brothers. The sequence analysis of a PCR fragment representing exon V amplified from genomic DNA of different kindreds of the pedigree revealed the mother as the only carrier indicating that the mutation has occurred de novo in the mother's germline. PLP gene (including the 8.8 kb intron I) rearrangements have been excluded by Southern blot hybridization and overlapping PCR amplification of genomic DNA