Recombinant plasmids carrying the glutamate dehydrogenase structural gene from Escherichia coli K-12.

Plasmid pRSP1, isolated from the Escherichia coli gene bank of Clarke and Carbon (1975), has been shown to complement the gdh-1 mutation that affects the synthesis of glutamate dehydrogenase (GDH) in the E. coli strain PA340. The GDH structural gene of E. coli is present on a 2.3-Md DNA fragment from the hybrid plasmid pRSP1 and certain of its derivatives. Polypeptides synthesized by minicells carrying some of these plasmids, enabled us to make a preliminary determination of the direction of transcription of the gdh gene on the cloned fragments.

Nucleotide sequence of the promoter and amino-terminal coding region of the glutamate dehydrogenase structural gene of Escherichia coli.

A 610-bp DNA fragment carrying the promoter and amino-terminal coding regions of the glutamate dehydrogenase (GDH) structural gene from Escherichia coli has been sequenced. The amino-terminal sequence of the enzyme was also determined to help localize the transcriptional and translational signals for this gene. Three possible promoters and a CRP binding site were identified by concensus criteria. The sequence of 102 amino acids at the amino terminus of the enzyme is compared with the amino acid sequence from other GDH enzymes.

Evidencias bioquimicas de la presencia del gene estructural de la deshidrogenasa glutamica de E. coli K-12 en plasmidos recombinantes. / Biochemical evidences of the presence of the structural gene of glutamic dehydrogenase of E. coli K-12 in recombinant plasmids

Utilizando pruebas de complementacion, electroforesis en una y dos dimensiones e inmunoprecipitacion especifica, fue posible demostrar la presencia del gene estructural que codifica para la enzima deshidrogenasa glutamica e E. coli en ciertos fragmentos de DNA del plasmido pRSPl y en algunos de sus derivados