Acyl-CoA Synthetase (ACOS) genes are related to 4-coumarate:CoA ligase (4CL) but have distinct functions. The Arabidopsis thaliana ACOS5 protein is in clade A of Arabidopsis ACOS proteins, the clade most closely related to 4CL proteins. This clade contains putative nonperoxisomal ACOS enzymes conserved in several angiosperm lineages and in the moss Physcomitrella patens. Although its function is unknown, ACOS5 is preferentially expressed in the flowers of all angiosperms examined. Here, we show that an acos5 mutant produced no pollen in mature anthers and no seeds by selffertilization and was severely compromised in pollen wall formation apparently lacking sporopollenin or exine. The phenotype was first evident at stage 8 of anther development and correlated with maximum ACOS5 mRNA accumulation in tapetal cells at stages 7 to 8. Green fluorescent protein-ACOS5 fusions showed that ACOS5 is located in the cytoplasm. Recombinant ACOS5 enzyme was active against oleic acid, allowing kinetic constants for ACOS5 substrates to be established. Substrate competition assays indicated broad in vitro preference of the enzyme for medium-chain fatty acids. We propose that ACOS5 encodes an enzyme that participates in a conserved and ancient biochemical pathway required for sporopollenin monomer biosynthesis that may also include the Arabidopsis CYP703A2 and MS2 enzymes.

The seven-gene human APOBEC3 (A3) cytidine deaminase locus came to the fore with the identification of APOBEC3G (A3G) as the interaction partner of the human immunodeficiency virus (HIV) Vif protein (8,16,26,29,30,43,57). These enzymes belong to a larger group that can edit nucleic acids, of which activation-induced cytidine deaminase (AICDA), responsible for class switch recombination and somatic hypermutation of rearranged immunoglobulin V region genes, is perhaps the most widely known (11). All functional A3 enzymes show specificity for single-stranded DNA (ssDNA). Since the reaction product is uridine (dU), A3 activity results in DNA peppered by C 3 U substitutions, referred to as hypermutants. Editing can range from a few cytidine targets to over 80% (2,3,8,16,26,29,30,49,54). To a good first approximation, all A3 enzymes preferentially edit ssDNA when the edited base is 5Ј flanked by thymidine or cytidine, i.e., TpC and CpC. In contrast, AICDA prefers GpC and ApC (2,

Oxycodone provided better analgesia but also more side effects, suggesting that the doses used in the present study may not be equipotent.

Enterococci possess capsular carbohydrate antigens that are targets of opsonic antibodies. These antigens may be used to develop alternative options for the treatment and prevention of enterococcal infections. The present study was done to analyze the diversity of capsular polysaccharides in Enterococcus faecalis. Four type-specific sera were used in an enzyme-linked immunosorbent assay format to detect polysaccharide antigen extracted from bacterial cell walls. A total of 55% of a collection of 29 E. faecalis strains could be grouped into one of four serogroups. Additional analysis of the strains by opsonophagocytic assays revealed agreement between the results of the two methods for 72% of the isolates. An additional four strains could be assigned to a serogroup on the basis of opsonic killing by sera with antibodies against the four prototypes strains, provisionally named CPS-A to CPS-D. The results of the two methods disagreed for one strain (4%). When the results of both methods were combined, 66% of the strains could be classified. One strain had to be assigned to two serogroups. The assignments to the four serogroups were confirmed by analysis of the genetic organization of the biosynthetic capsular polysaccharide (cps) locus. All strains grouped into serotypes CPS-A and CPS-B possessed only the cpsA and cpsB genes, while all strains grouped into serogroups CPS-C and CPS-D possessed an additional eight or nine genes. Our results suggest the existence of a limited number of E. faecalis capsule serotypes, and we provisionally propose four serotypes, named CPS-A to CPS-D, and the respective prototype strains for these families.