title: Effect of the increased stability of the penicillin amidase mRNA on the protein expression levels.
abstract: Several factors at transcriptional, post-transcriptional or post-translational level determine the fate of a target protein and can severely restrict its yield. Here, we focus on the post-transcriptional regulation of the biosynthesis of the periplasmic protein, penicillin amidase (PA). The PA mRNA stability was determined under depleted RNase conditions in strains carrying single or multiple RNase deletions. Single deletion of the endonuclease RNase E yielded, as the highest, a fourfold stabilization of the PA mRNA. This effect, however, was reduced twice at post-translational level. The RNase II, generating secondary exonucleolytic cleavages in the mRNA, although not significantly influencing the PA mRNA decay, led also to an increase of the amount of mature PA. The non-proportional correlation between increased mRNA longevity and amount of active enzyme propose that the rational strategies for yield improvement must be based on a simultaneous tuning of more than one yield restricting factor.
authors.affiliation: Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Apartado 127, 2781-901 Oeiras, Portugal.
authors.forename: Sandra C
authors.initials: SC
authors.lastname: Viegas
authors.forename: Dorothea
authors.initials: D
authors.lastname: Schmidt
authors.forename: Volker
authors.initials: V
authors.lastname: Kasche
authors.forename: Cecília M
authors.initials: CM
authors.lastname: Arraiano
authors.forename: Zoya
authors.initials: Z
authors.lastname: Ignatova
mesh_terms: D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation; D010399:Penicillin Amidase / Q000235:genetics* / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D012323:RNA Processing, Post-Transcriptional; D020871:RNA Stability; D012333:RNA, Messenger / Q000378:metabolism*; D012260:Ribonucleases / Q000378:metabolism
chemical_list: D029968:Escherichia coli Proteins; D012333:RNA, Messenger; D012260:Ribonucleases; D010399:Penicillin Amidase