Excess histidine enzymes cause AICAR-independent filamentation in Escherichia coli |
| |
Authors: | Niels Frandsen Richard D'Ari |
| |
Institution: | 1. Institut Jacques Monod (C.N.R.S., Université Paris 7), 2, place Jussieu, F-75251, Paris Cedex 05, France
|
| |
Abstract: | High-level expression of the hisHAFI genes in Escherichia coli, cloned under the control of an IPTG-inducible promoter, caused filamentation, as previously reported in Salmonella typhimurium. We speculated that this filamentation might be produced by an action of the HisH and HisF enzymes on their product AICAR (amino-imidazole carboxamide riboside 5′-phosphate), a histidine by-product and normal purine precursor, possibly by favouring the formation of ZTP, the triphosphate derivative of AICAR. However, filamentation occured even in the absence of carbon flow through the histidine and purine pathways, as observed in a hisG purF strain lacking the first enzyme in each pathway. Filamentation thus does not require either the normal substrate or products of the overproduced histidine enzymes and must reflect another activity. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|