Presence of an inducible semicarbazide-sensitive amine oxidase in Mycobacterium sp. Strain JC1 DSM 3803 grown on benzylamine

Mycobacterium sp. strain JC1 was capable of growth on benzylamine as a sole source of carbon and energy. The primary deamination of benzylamine was mediated by an inducible amine oxidase, which can also oxidize tyramine, histamine, and dopamine. Inhibitor study identified this enzyme as a copper-containing amine oxidase sensitive to semicarbazide.     

NMR study of hydrogen exchange during the B-Z transition of a DNA duplex induced by the Zα domains of yatapoxvirus E3L

The Yaba-like disease viruses (YLDV) are members of the Yatapoxvirus family and have double-stranded DNA genomes. The E3L protein, which is essential for pathogenesis in the vaccinia virus, consists of two domains: an N-terminal Z-DNA binding domain and a C-terminal RNA binding domain. The crystal structure of the E3L orthologue of YLDV (yabZα_E3L) bound to Z-DNA revealed that the overall structure of yabZα_E3L and its interaction with Z-DNA are very similar to those of hZα_ADAR1. Here we have performed NMR hydrogen exchange experiments on the complexes between yabZα_E3L and d(CGCGCG)₂ with a variety of protein-to-DNA molar ratios. This study revealed that yabZα_E3L could efficiently change the B-form helix of the d(CGCGCG)₂ to left-handed Z-DNA via the active-mono B-Z transition pathway like hZα_ADAR1.     

Dextran molecular size and degree of branching as a function of sucrose concentration,pH, and temperature of reaction of Leuconostoc mesenteroides B-512FMCM dextransucrase

Reactions of Leuconostoc mesenteroides B-512FMCM dextransucrase with increasing concentrations of sucrose, from 0.1 to 4.0 M, gave a decreasing amount of high-molecular weight dextran (HMWD) (>10(6) Da) with a concomitant increase in low-molecular weight dextran (LMWD) (<10(5) Da). At 0.1 M sucrose, pH 5.5, and 28 degrees C, 99.8% of the dextran had a MW>10(6) Da and at 4.0 M sucrose, 69.9% had a MW<10(5) Da and 30.1% had a MW>10(6) Da, giving a bimodal distribution. The degree of branching increased from 5% for 0.1 M sucrose to 16.6% for 4.0 M sucrose. The temperature had very little effect on the size of the dextran, which was >10(6) Da, but it had a significant effect on the degree of branching, which was 4.8% at 4 degrees C and increased to 14.7% at 45 degrees C. Both the molecular weight (MW) and the degree of branching were not significantly affected by different pH values between 4.5 and 6.0.     

CbiX-homologous protein (CbiXhp), a metal-binding protein, from Streptomyces seoulensis is involved in expression of nickel-containing superoxide dismutase

To find the accessory proteins participating in expression and maturation of nickel-containing superoxide dismutase (NiSOD), a metal-binding protein (CbiXhp) homologous to cobaltochelatase (CbiX) of Bacillus megaterium was isolated by nickel-nitrilotriacetic acid resin from Streptomyces seoulensis. The deduced amino acid sequence of cbiXhp showed 87% and 39% identity to CbiX of Streptomyces coelicolor and that of B. megaterium, respectively. Overexpression of CbiXhp increased the activity and the expression of NiSOD in the presence and absence of nickel, but to a lesser extent in its absence. This result indicates that CbiXhp is involved in the expression of NiSOD.     

Dual mechanisms of pestiviral superinfection exclusion at entry and RNA replication

For many viruses, primary infection has been shown to prevent superinfection by a homologous second virus. In this study, we investigated superinfection exclusion of bovine viral diarrhea virus (BVDV), a positive-sense RNA pestivirus. Cells acutely infected with BVDV were protected from superinfection by homologous BVDV but not with heterologous vesicular stomatitis virus. Superinfection exclusion was established within 30 to 60 min but was lost upon passaging of persistently infected cells. Superinfecting BVDV failed to deliver a translatable genome into acutely infected cells, indicating a block in viral entry. Deletion of structural protein E2 from primary infecting BVDV abolished this exclusion. Bypassing the entry block by RNA transfection revealed a second block at the level of replication but not translation. This exclusion did not require structural protein expression and was inversely correlated with the level of primary BVDV RNA replication. These findings suggest dual mechanisms of pestivirus superinfection exclusion, one at the level of viral entry that requires viral glycoprotein E2 and a second at the level of viral RNA replication.