Search results for "Tryptophan biosynthesis"

THE SMALL PROTEIN SCO2038 CONTROLS TRYPTOPHAN BIOSYNTHESIS AND DIFFERENTIATION IN STREPTOMYCES COELICOLOR

The cellular regulatory factors comprise regulatory proteins, small RNA and small proteins. It is known that the product of small orfs (smorfs) can regulate the translation of downstream elements and also can encode functional peptides involved in the regulation of specific pathways (Ladoukakis E. et al.,2011). In particular, in the model streptomycete Sfreptomyces coelicolor, smorfs (about 100-300 nucleotides) were identified in some amino acid biosynthetic gene clusters such as in the tryptophan trpCXBA locus (Limauro D. et al., I 990; Hu DS. et al., 1999). In S. coelicolor the molecular mechanisms that regulate tryptophan (Trp) biosynthesis are poorly understood and, unlike the trp opero…

TrpM, a Small Protein Modulating Tryptophan Biosynthesis and Morpho-Physiological Differentiation in Streptomyces coelicolor A3(2).

2016

In the model actinomycete Streptomyces coelicolor A3(2), small open reading frames encoding proteins with unknown functions were identified in several amino acid biosynthetic gene operons, such as SCO2038 (trpX) in the tryptophan trpCXBA locus. In this study, the role of the corresponding protein in tryptophan biosynthesis was investigated by combining phenotypic and molecular analyses. The 2038KO mutant strain was characterized by delayed growth, smaller aerial hyphae and reduced production of spores and actinorhodin antibiotic, with respect to the WT strain. The capability of this mutant to grow on minimal medium was rescued by tryptophan and tryptophan precursor (serine and/or indole) su…

The small protein SCO2038 controls Streptomyces coelicolor differentiation by modulating tryptophan biosynthesis

2015

Background In Streptomyces coelicolor amino acid metabolism is an important clue of the morphological and physiological differentiation program and, differently from other bacteria, the expression of amino acid biosynthetic genes is not subjected to endproduct negative regulation. In some amino acid biosynthetic gene clusters, such as tryptophan, histidine and proline, small orfs (about 100-300 nucleotides) were identified. These small orfs, such as sco2038, encode proteins whose cellular role have to be elucidated to highlight possible novel and crucial molecular mechanisms controlling amino acid synthesis and, thus, differentiation program. Objectives The aims of this work are: 1. the und…

The genomic sequence of Exiguobacterium chiriqhucha str. N139 reveals a species that thrives in cold waters and extreme environmental conditions

2017

We report the genome sequence of Exiguobacterium chiriqhucha str. N139, isolated from a high-altitude Andean lake. Comparative genomic analyses of the Exiguobacterium genomes available suggest that our strain belongs to the same species as the previously reported E. pavilionensis str. RW-2 and Exiguobacterium str. GIC 31. We describe this species and propose the chiriqhucha name to group them. ‘Chiri qhucha’ in Quechua means ‘cold lake’, which is a common origin of these three cosmopolitan Exiguobacteria. The 2,952,588-bp E. chiriqhucha str. N139 genome contains one chromosome and three megaplasmids. The genome analysis of the Andean strain suggests the presence of enzymes that confer E. ch…

Exiguobacterium pavilionensis str. N139, a halotolerant, UV-B and metal resistant bacteria from a high-altitude Andean lake

2016

We report the genome sequence of Exiguobacterium pavilionensis str. N139, isolated from a high-altitude Andean lake. The 2,952,588-bp genome contains one chromosome and three megaplasmids. The genome analysis suggests the presence of enzymes that confer E. pavilionensis str. N139 the ability to grow under multiple environmental extreme conditions, including high concentrations of different metals and high ultraviolet B radiation. Moreover, the regulation of its tryptophan biosynthesis suggests that novel pathways remain to be discovered, and that these pathways might be fundamental in the amino acid metabolism of the microbial community from Laguna Negra, Argentina .