Reduction of the Edited Domain of the Mitochondrial A6 Gene for ATPase Subunit 6 in Trypanosomatidae

The sequence of mitochondrial A6 (MURF4) was compared for several trypanosomatids in order to assess the reduction of the edited domain (ED). The association between the ED reduction and the phylogenetic position of a species proved to be less tight than believed earlier. Compared with digenetic species, monogenetic ones more often displayed ED reduction and had smaller ED.     

Landscape-ecological patterns of earthworm (Oligochaeta, Lumbricidae) distribution in the soils of Southern Middle Siberia

The structures of earthworm communities and their distribution in the southern ecosystems of Middle Siberia have been studied at the local (biogenocenotic), topological (facial), and regional landscape levels. Long-term observation data at fixed sites have been used to construct map charts that portray the landscape-ecological patterns for variations in the quantitative characteristics and species compositions of lumbricides, which depend on abiotic factors and the anthropogenic impact.     

Antimicrobial Activity of Geometric Isomers of Etherolenic Acid—the Products of Plant Lipoxygenase Cascade

Data on the influence of the double bond geometry on the antimicrobial properties of different isomers of etherolenic acid against phytopathogenic bacteria are presented. (ω5Z)-Etherolenic acid possesses bactericidal properties against Xanthomonas campestris ssp. vesicatoria, Pseudomonas syringae ssp. tomato, Pectobacterium atrosepticum SCRI1043; the etherolenic and (11Z)-etherolenic acids possess only bacteriostatic properties.     

The structure of soil mesopopulation bearing on climatic changes and anthropogenic impact on geosystems at the taiga-steppe contact in the Baikal region

The paper gives landscape-ecological analysis of soil population in steppe and forest geosystems of the Baikal region and specific Baikalian climate. The changes in invertebrate communities under anthropogenic impact against the background of increased air and soil temperatures have been characterized.     

Structure of Rab escort protein-1 in complex with Rab geranylgeranyltransferase

Posttranslational geranylgeranylation of Rab GTPases is catalyzed by Rab geranylgeranyltransferase (RabGGTase), which consists of a catalytic alpha/beta heterodimer and an accessory Rab escort protein (REP). The crystal structure of isoprenoid-bound RabGGTase complexed to REP-1 has been solved to 2.7 A resolution. The complex interface buries a surprisingly small surface area of ca. 680 A and is unexpectedly formed by helices 8, 10, and 12 of the RabGGTase alpha subunit and helices D and E of REP-1. We demonstrate that the affinity of RabGGTase for REP-1 is allosterically regulated by phosphoisoprenoid via a long-range trans-domain signal transduction event. Comparing the structure of REP-1 with the closely related RabGDI, we conclude that the specificity of the REP:RabGGTase interaction is defined by differently positioned phenylalanine residues conserved in the REP and GDI subfamilies.     

Reduction of the edited domain of the mitochondrial A6 gene for ATPase subunit 6 in Trypanosomatidae

The sequence of mitochondrial A6 (MURF4) was compared for several trypanosomatids in order to assess the reduction of the edited domain (ED). The association between the ED reduction and the phylogenetic position of a species proved to be less tight than believed earlier. Compared with digenetic species, monogenetic ones more often displayed ED reduction and had smaller ED.     

Double function hydroperoxide lyases/epoxyalcohol synthases (CYP74C) of higher plants: identification and conversion into allene oxide synthases by site-directed mutagenesis

The CYP74C subfamily of fatty acid hydroperoxide transforming enzymes includes hydroperoxide lyases (HPLs) and allene oxide synthases (AOSs). This work reports a new facet of the putative CYP74C HPLs. Initially, we found that the recombinant CYP74C13_MT (Medicago truncatula) behaved predominantly as the epoxyalcohol synthase (EAS) towards the 9(S)-hydroperoxide of linoleic acid. At the same time, the CYP74C13_MT mostly possessed the HPL activity towards the 13(S)-hydroperoxides of linoleic and α-linolenic acids. To verify whether this dualistic behaviour of CYP74C13_MT is occasional or typical, we also examined five similar putative HPLs (CYP74C). These were CYP74C4_ST (Solanum tuberosum), CYP74C2 (Cucumis melo), CYP74C1_CS and CYP74C31 (both of Cucumis sativus), and CYP74C13_GM (Glycine max). All tested enzymes behaved predominantly as EAS toward 9-hydroperoxide of linoleic acid. Oxiranyl carbinols such as (9S,10S,11S,12Z)-9,10-epoxy-11-hydroxy-12-octadecenoic acids were the major EAS products. Besides, the CYP74C31 possessed an additional minor 9-AOS activity. The mutant forms of CYP74C13_MT, CYP74C1_CS, and CYP74C31 with substitutions at the catalytically essential domains, namely the “hydroperoxide-binding domain” (I-helix), or the SRS-1 domain near the N-terminus, showed strong AOS activity. These HPLs to AOSs conversions were observed for the first time. Until now a large part of CYP74C enzymes has been considered as 9/13-HPLs. Notwithstanding, these results show that all studied putative CYP74C HPLs are in fact the versatile HPL/EASs that can be effortlessly mutated into specific AOSs.