title: In vivo aggregation of a single enzyme limits growth of Escherichia coli at elevated temperatures.
abstract: The formation of protein aggregates is associated with unfolding and denaturation of proteins. Recent studies have indicated that, in Escherichia coli, cellular proteins tend to aggregate when the bacteria are exposed to thermal stress. Here, we show that the aggregation of one single E. coli cytoplasmic protein limits growth at elevated temperatures in minimal media. Homoserine trans-succinylase (HTS), the first enzyme in the methionine biosynthetic pathway, aggregates at temperatures higher than 44 degrees C in vitro. Above this temperature, we can also observe in vivo aggregation that results in the complete disappearance of the enzyme from the soluble fraction. Moreover, reducing the in vivo level of HTS aggregation enables growth at non-permissive temperatures. This is the first demonstration of the physiological role of aggregation of a specific protein in the growth of wild-type bacteria.
authors.affiliation: Department of Molecular Microbiology and Biotechnology, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Israel.
authors.forename: Eyal
authors.initials: E
authors.lastname: Gur
authors.forename: Dvora
authors.initials: D
authors.lastname: Biran
authors.forename: Ehud
authors.initials: E
authors.lastname: Gazit
authors.forename: Eliora Z
authors.initials: EZ
authors.lastname: Ron
mesh_terms: D000217:Acyltransferases / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D002942:Circular Dichroism; D003470:Culture Media; D004795:Enzyme Stability; D004926:Escherichia coli / Q000201:enzymology / Q000254:growth & development*; D006714:Homoserine / Q000378:metabolism; D051082:Homoserine O-Succinyltransferase; D008715:Methionine / Q000378:metabolism; D008744:Methylamines / Q000494:pharmacology; D011489:Protein Denaturation / Q000187:drug effects; D017510:Protein Folding; D013696:Temperature
chemical_list: D003470:Culture Media; D008744:Methylamines; D006714:Homoserine; D008715:Methionine; D000217:Acyltransferases; D051082:Homoserine O-Succinyltransferase; C005855:trimethyloxamine