The gene encoding alternansucrase (ASR) from Leuconostoc mesenteroides NRRL B-1355, an original sucrose glucosyltransferase (GTF) specific to alternating alpha-1,3 and alpha-1,6 glucosidic bond synthesis, was cloned, sequenced and expressed into Escherichia coli. Recombinant enzyme catalyzed oligoalternan synthesis from sucrose and maltose acceptor. From sequence comparison, it appears that ASR possesses the same domains as those described for GTFs specific to either contiguous alpha-1,3 osidic bond or contiguous alpha-1,6 osidic bond synthesis. However, the variable region and the glucan binding domain are longer than in other GTFs (by 100 and 200 amino acids respectively). The N-catalytic domain which presents 49% identity with the other GTFs from L. mesenteroides possesses the three determinants potentially involved in the glucosyl enzyme formation.
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http://dx.doi.org/10.1111/j.1574-6968.2000.tb08878.x | DOI Listing |
Sci Transl Med
January 2025
Department of Cell Biology and Physiology, Washington University School of Medicine, Saint Louis, MO 63110, USA.
Proc Natl Acad Sci U S A
February 2025
Molecular Genetics, Institute of Biology, Faculty of Life Sciences, Humboldt Universität zu Berlin, Berlin 10115, Germany.
The chloroplast genome encodes key components of the photosynthetic light reaction machinery as well as the large subunit of the enzyme central for carbon fixation, Ribulose-1,5-bisphosphat-carboxylase/-oxygenase (RuBisCo). Its expression is predominantly regulated posttranscriptionally, with nuclear-encoded RNA-binding proteins (RBPs) playing a key role. Mutants of chloroplast gene expression factors often exhibit impaired chloroplast biogenesis, especially in cold conditions.
View Article and Find Full Text PDFPLoS Biol
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Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts, United States of America.
RNA interference (RNAi) mediates antiviral defense in many eukaryotes. Caenorhabditis elegans mutants that disable RNAi are more sensitive to viral infection. Many mutants that enhance RNAi have also been identified; these mutations may reveal genes that are normally down-regulated in antiviral defense.
View Article and Find Full Text PDFRice (N Y)
January 2025
College of Agronomy, Anhui Agricultural University, Hefei, 230000, China.
Panicle elongation length (PEL), which determines panicle exsertion, is an important outcrossing-related trait. Mining genes controlling PEL in rice (Oryza sativa L.) has great practical significance in breeding cytoplasmic male sterility (CMS) lines with increased PEL and simplified, high-efficiency seed production.
View Article and Find Full Text PDFAppl Microbiol Biotechnol
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Chair of Microbiology, Technical University of Munich, TUM School of Life Science, Emil-Ramann-Str. 4, 85354, Freising, Germany.
The anaerobic bacterium Clostridium cellulovorans is a promising candidate for the sustainable production of biofuels and platform chemicals due to its cellulolytic properties. However, the genomic engineering of the species is hampered because of its poor genetic accessibility and the lack of genetic tools. To overcome this limitation, a protocol for triparental conjugation was established that enables the reliable transfer of vectors for markerless chromosomal modification into C.
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