Many protein-encoding genes of African trypanosomes are transcribed as large polycistronic pre-mRNAs that are processed into individual mRNAs containing a 5' spliced leader and 3' poly(A). The 45-to 60-kb pre-mRNAs encoding some variant surface glycoproteins (VSGs) contain as many as eight unrelated coding regions. Here we identify the promoter for a metacyclic VSG gene that is expressed without duplication in a bloodstream trypanosome clone. This 70-bp promoter is located 2 kb upstream of the telomere-linked VSG gene and directs the synthesis of a monocistronic VSG pre-mRNA lacking the 5' spliced leader. Its sequence only slightly resembles those of other known trypanosome promoters, but it does cross-hybridize with several related sequences elsewhere in the genome. These results suggest that a new class of trypanosome promoters has been found, whose function is to initiate monocistronic transcription of those VSG genes normally expressed during the metacyclic stage.

To date, two classes of mouse major urinary protein (MUP)-encoding genes have been described, the expressed genes and the intervening-sequence-containing pseudogenes. The data presented in this paper define a third class, the silent Mup genes, which are potentially functional but appear not to be expressed under normal circumstances. We describe a MUP subfamily (Mup-1.5) containing two genes, Mup-i.Sa and Mup-1.5b, that are nearly identical, differing at only three positions (>99.9% identity) over the entire 4-

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It was found that enzyme from a microbial strain, Monocillium spp. ATCC 20621, catalyzed the oxidative reaction of rifamycin B to form rifamycin O. The identification of the reaction products suggested that the reaction proceeded by the oxidative cyclization of rifamycin B to give rifamycin O, which spontaneously hydrolyzed to rifamycin S in neutral aqueous milieu. The characteristic of the enzyme was different as compared with that of other polyphenol oxidases such as laccase. It is proposed that this new type of enzyme be classified into a subgroup EC 1.10.3.6 with a trival name rifamycin B oxidase.

Many protein-encoding genes of African trypanosomes are transcribed as large polycistronic pre-mRNAs that are processed into individual mRNAs containing a 5' spliced leader and 3' poly(A). The 45- to 60-kb pre-mRNAs encoding some variant surface glycoproteins (VSGs) contain as many as eight unrelated coding regions. Here we identify the promoter for a metacyclic VSG gene that is expressed without duplication in a bloodstream trypanosome clone. This 70-bp promoter is located 2 kb upstream of the telomere-linked VSG gene and directs the synthesis of a monocistronic VSG pre-mRNA lacking the 5' spliced leader. Its sequence only slightly resembles those of other known trypanosome promoters, but it does cross-hybridize with several related sequences elsewhere in the genome. These results suggest that a new class of trypanosome promoters has been found, whose function is to initiate monocistronic transcription of those VSG genes normally expressed during the metacyclic stage.

A partially constitutive mutant strain for penicillin amidase production was derived from the parent strain Bacillus megaterium ATCC 14945 by treatment with UV light. The mutant (B. megaterium KFCC 10029) showed two phenotypical changes in the mode of penicillim amidase production and in the size of cell chains. While the parent strain produced penicillin amidase only in the presence of an inducer, phenylacetic acid, the mutant strain could produce the enzyme without the inducer and the enzyme titer increased three to four times as much as that in the presence of the inducer. The mutant appeared as isolated single cells or short chains on the nutrient agar medium, whereas the parent strain usually appeared as long chains of cells. The composition of media was optimized including the inducer concentration. After finding the optimal sets of operating conditions with regard to the pH adjustment and the inducer addition time in a submerged culture, we were able to increase the enzyme productivity 7 -8 times that without pH control. Although the correlation between two phenotypical changes is not yet clear, the mutant strain can be used as a potent producer of penicillin amidase.

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