The alpha-glucosyltransferases of bacteriophages T2, T4 and T6. A comparison of their primary structures

Summary With the aim of comparing the primary structures of gene products coded for by T-even bacteriophages we constructed clone libraries of the DNAs of bacteriophages T2 and T6. Using hybrid M13 phages carrying the gene for the T4-coded -glucosyl transferase (gt) we isolated corresponding T2 and T6 clones. The nucleotide sequences of the three gt genes and the amino acid sequences derived were compared. The differences between the genes and their products are discussed in terms of structure, function and evolutionary aspects.Abbreviations bp base pair - gt glucosyl transferase - HMC 5-hydroxymethyl cytosine - orf open reading frame - Xgal 5-bromo-4-chloro-3-indolyl--d-galactoside     

T4-induced alpha- and beta-glucosyltransferase: cloning of the genes and a comparison of their products based on sequencing data.

Bacteriophage T4 alpha- and beta-glucosyltransferases link glucosyl units to the 5-HMdC residues of its DNA. The monoglucosyl group in alpha-linkage predominates over the one in beta linkage. Having recently reported on the nucleotide sequence of gene alpha gt (1) we now determined the nucleotide sequence of gene beta gt. The genes were each cloned on a high expression vector under the control of the lambda pL promoter. After thermo-induction the proteins were isolated and purified to homogeneity. To verify that the translational starting sites and the proposed reading frames are effective in vivo the sequence of the first 31 amino acid residues from gp alpha gt and the first 30 amino acid residues from gp beta gt were determined by Edman degradation. The primary structures of the two proteins seem to have only limited structural similarities. The results are discussed comparing secondary structure predictions and homologies with other proteins from the protein sequence database of the Protein Identification Resource.     

Changes in certain kinetic properties of hepatic microsomal aniline hydroxylase and ethylmorphine demethylase associated with postnatal development and maturation in male rats

1. Changes in certain kinetic properties (V(max.) and apparent K(m)) of hepatic microsomal mixed-function oxidases have been studied as a function of postnatal development and maturation in male rats. 2. Microsomal cytochrome P-450 content changed only slightly between 1 and 12 weeks of age. 3. Aniline hydroxylase activity (V(max.)) increased abruptly between 1 and 2 weeks of age to greater than adult activities and then returned to a plateau value between 4(1/2) and 12 weeks of age. Ethylmorphine demethylase activity remained low and relatively constant between 1 and 3 weeks of age and then increased markedly ( approximately 100%) between 3 and 4(1/2) weeks. 4. The apparent Michaelis constant (K(m)) for aniline hydroxylation increased almost linearly with time between 1 and 6 weeks of age and tended to reach a plateau value thereafter. The apparent K(m) for ethylmorphine demethylation increased between 1 and 3 weeks of age and then decreased abruptly to a constant value between 6 and 12 weeks. 5. The data indicate that developmental changes in the activity of these microsomal oxidases do not correlate temporally with each other or with changes in microsomal cytochrome P-450 content. 6. The most dramatic changes in enzyme activity were associated with early development (1-3 weeks) and weaning (3-4 weeks). 7. Changes in weight of seminal vesicle, a criterion of sexual maturation in male rats, were most prominent between 6 and 8 weeks of age and thus appeared to be separated in time from the prominent changes in enzyme activity.     

The submicrosomal distribution of hepatic uridine diphosphate glucuronyltransferases in the rabbit

1. Rabbit liver microsomes were subfractionated into rough- and smooth-surfaced types, and glucuronyltransferase activity in each microsomal subfraction was determined with p-nitrophenol, o-aminophenol and phenolphthalein as substrates. The glucuronyltransferase activity measured with p-nitrophenol and o-aminophenol as substrates was localized predominantly in rough-surfaced microsomes. Glucuronyltransferase measured with phenolphthalein as substrate was equally present in rough- and smooth-surfaced microsomes. 2. Phenobarbital pretreatment of rabbits did not stimulate any of the glucuronyltransferase activities measured in either rough- or smooth-surfaced microsomes. 3. Preincubation of rabbit liver microsomes for 30-60min. at 37 degrees under oxygen did not cause any loss of glucuronyltransferase activity. Such preincubation caused either no change or increased enzyme activity in both submicrosomal fractions. The relative distribution of transferase activity in rough- and smooth-surfaced microsomes was not affected by preincubation.     

Inhibitory Effects of Secondary Metabolites from the Red Alga Delisea pulchra on Swarming Motility of Proteus mirabilis

Abnormal, uncoordinated swarming motility of the opportunistic human pathogen Proteus mirabilis was seen when a crude extract of the Australian red alga Delisea pulchra was added to the medium. This occurred at concentrations at which growth rate, swimming motility, cell elongation, polynucleation, and hyperflagellation were not affected. One halogenated furanone from D. pulchra inhibited swarming motility at concentrations that did not affect growth rate and swimming motility. Other structurally similar D. pulchra furanones had no effect on swarming, suggesting considerable specificity in the effects of furanones on swarming motility by P. mirabilis.     

Characterization of 24 porcine (dA-dC)n-(dT-dG)n microsatellites: genotyping of unrelated animals from four breeds and linkage studies

Twenty-four PCR primer pairs were designed for the detection of porcine microsatellites. Polymorphism was investigated in 76 unrelated animals from four different breeds: Duroc, Landrace, Hampshire, and Yorkshire. Compared with human microsatellites, a general lower heterozygosity was detected; however, for each microsatellite a significant variation between breeds in number of alleles and heterozygosity was seen. Mean heterozygosity was found to be significantly higher (P<0.01%) in the Yorkshire breed than in the other three breeds. Linkage analyses with the CEPH linkage packet were performed in a backcross family comprising 45 animals, of which 43 had informative meioses. Ten of the microsatellites could be assigned to six different linkage groups, demonstrating that linkage mapping with microsatellites can be carried out with great efficiency in a relatively small number of animals. Four of the linkage groups represent Chromosomes (Chrs) 4, 6, 7, and 8 respectively, while two linkage groups are unassigned.The nucleotide sequence data reported in this paper have been submitted to GenBank and have been assigned the accession numbers listed in Table 1.     

Ethane and n-pentane in exhaled breath are biomarkers of exposure not effect

The relationship of exhaled ethane and n-pentane to exhaled NO, carbonylated proteins, and indoor/outdoor atmospheric pollutants were examined in order to evaluate ethane and n-pentane as potential markers of airway inflammation and/or oxidative stress. Exhaled NO and carbonylated proteins were found to have no significant associations with either ethane (p = 0.96 and p = 0.81, respectively) or n-pentane (p = 0.44 and 0.28, respectively) when outliers were included. In the case where outliers were removed n-pentane was found to be inversely associated with carbonylated proteins. Exhaled hydrocarbons adjusted for indoor hydrocarbon concentrations were instead found to be positively associated with air pollutants (NO, NO₂ and CO), suggesting pollutant exposure is driving exhaled hydrocarbon concentrations. Given these findings, ethane and n-pentane do not appear to be markers of airway inflammation or oxidative stress.