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Balanced biosynthesis of major membrane components through regulated degradation of the committed enzyme of lipid A biosynthesis by the AAA protease FtsH (HflB) in Escherichia coli
Author(s) -
Ogura Teru,
Inoue Koichi,
Tatsuta Takashi,
Suzaki Toshinobu,
Karata Kiyonobu,
Young Katherine,
Su LinHui,
Fierke Carol A.,
Jackman Jane E.,
Raetz Christian R. H.,
Coleman Jack,
Tomoyasu Toshifumi,
Matsuzawa Hiroshi
Publication year - 1999
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1046/j.1365-2958.1999.01221.x
Subject(s) - biology , biosynthesis , escherichia coli , biochemistry , protease , lipid a , mutant , enzyme , bacterial outer membrane , lipopolysaccharide , acyl carrier protein , gene , endocrinology
The suppressor mutation, named sfhC21 , that allows Escherichia coli ftsH null mutant cells to survive was found to be an allele of fabZ encoding R ‐3‐hydroxyacyl‐ACP dehydrase, involved in a key step of fatty acid biosynthesis, and appears to upregulate the dehydrase. The ftsH1 (Ts) mutation increased the amount of lipopolysaccharide at 42°C. This was accompanied by a dramatic increase in the amount of UDP‐3‐ O ‐( R ‐3‐hydroxymyristoyl)‐ N ‐acetylglucosamine deacetylase [the lpxC ( envA ) gene product] involved in the committed step of lipid A biosynthesis. Pulse‐chase experiments and in vitro assays with purified components showed that FtsH, the AAA‐type membrane‐bound metalloprotease, degrades the deacetylase. Genetic evidence also indicated that the FtsH protease activity for the deacetylase might be affected when acyl‐ACP pools were altered. The biosynthesis of phospholipids and the lipid A moiety of lipopolysaccharide, both of which derive their fatty acyl chains from the same R ‐3‐hydroxyacyl‐ACP pool, is regulated by FtsH.