title: Pleiotropic effect of the SCO2127 gene on the glucose uptake, glucose kinase activity and carbon catabolite repression in Streptomyces peucetius var. caesius.
abstract: SCO2127 and SCO2126 (glkA) are adjacent regions located in Streptomyces coelicolor DNA. glkA encodes glucose kinase (Glk), which has been implicated in carbon catabolite repression (CCR) in the genus Streptomyces. In this work, the glkA and SCO2127 genes from S. coelicolor were used, either individually or together, to transform three mutants of Streptomyces peucetius var. caesius resistant to CCR. These mutants present decreased levels of Glk, and deficiency in glucose transport. When the mutants were transformed with a plasmid containing the SCO2127 sequence, glucose uptake and Glk activity values were increased to levels similar to or higher than those of the original strain, and each strain regained sensitivity to CCR. This result was surprising considering that the putative SCO2127 amino acid sequence does not seem to encode a glucose permease or a Glk. In agreement with these results, an increase in glkA mRNA levels was observed in a CCR-resistant mutant transformed with SCO2127 compared with those of the original strain and the CCR-resistant mutant itself. As expected, recombinants containing the glkA sequence reverted Glk to normal activity values, but glucose uptake remained deficient. The data suggest that the SCO2127 gene product enhances transcription of both genes, and support the first specific role for this region in Streptomyces species. The physiological consequence of this effect is an increase in the glucose catabolites that may be involved in eliciting CCR in this genus.
authors.affiliation: Departamento de Biología Molecular y Biotecnología del Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México, DF CP 04510, Mexico.
authors.forename: Silvia
authors.initials: S
authors.lastname: Guzmán
authors.affiliation: Departamento de Biología Molecular y Biotecnología del Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México, DF CP 04510, Mexico.
authors.forename: Alonso
authors.initials: A
authors.lastname: Carmona
authors.affiliation: Departamento de Biología Molecular y Biotecnología del Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México, DF CP 04510, Mexico.
authors.forename: Laura
authors.initials: L
authors.lastname: Escalante
authors.affiliation: Departamento de Biología Molecular y Biotecnología del Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México, DF CP 04510, Mexico.
authors.forename: Iveta
authors.initials: I
authors.lastname: Imriskova
authors.affiliation: Departamento de Biología Molecular y Biotecnología del Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México, DF CP 04510, Mexico.
authors.forename: Ruth
authors.initials: R
authors.lastname: López
authors.affiliation: Departamento de Biología Molecular y Biotecnología del Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México, DF CP 04510, Mexico.
authors.forename: Romina
authors.initials: R
authors.lastname: Rodríguez-Sanoja
authors.affiliation: Departamento de Biología Molecular y Biotecnología del Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México, DF CP 04510, Mexico.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Ruiz
authors.affiliation: Departamento de Biología Molecular y Biotecnología del Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México, DF CP 04510, Mexico.
authors.forename: Luis
authors.initials: L
authors.lastname: Servín-González
authors.affiliation: Departamento de Biología Molecular y Biotecnología del Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México, DF CP 04510, Mexico.
authors.forename: Sergio
authors.initials: S
authors.lastname: Sánchez
authors.affiliation: Departamento de Biología Molecular y Biotecnología del Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México, DF CP 04510, Mexico.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Langley
mesh_terms: D000963:Antimetabolites / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D002244:Carbon / Q000378:metabolism / Q000494:pharmacology*; D003470:Culture Media; D003847:Deoxyglucose / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D005941:Glucokinase / Q000235:genetics / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism*; D009154:Mutation; D012329:RNA, Bacterial / Q000378:metabolism; D011995:Recombination, Genetic; D013302:Streptomyces / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D000963:Antimetabolites; D001426:Bacterial Proteins; D003470:Culture Media; D012329:RNA, Bacterial; D002244:Carbon; D003847:Deoxyglucose; C096446:GlkA protein, Bacteria; D005941:Glucokinase; D005947:Glucose