Publisher Summary
Bacteria are versatile tools for the study of metabolic pathways. This is especially true for the gram-negative Escherichia coli. These bacteria are easy to grow, and the growth conditions can be controlled and manipulated by the investigator. They are suitable for genetic manipulation and their genome sequence is available. E. coli is the most extensively studied bacterium, and the genes and enzymes of fatty acid and phospholipid metabolism were first delineated using this organism. Phospholipid synthesis requires significant energy investment by the cell, and the advantages of maintaining fine control over the pathway are obvious. The pathway in most bacteria is catalyzed by a series of discrete proteins: the enzymes of fatty acid synthesis are cytosolic, while those of membrane phospholipid synthesis are mainly integral inner membrane proteins. The differences between the bacterial and mammalian enzymes offer attractive targets for novel anti-microbial drugs. The enzymes of fatty acid synthesis are soluble proteins whose individual activities can be assayed in crude cell extracts or purified preparations. This is markedly different from the mammalian fatty acid synthase, a large multi-functional polypeptide with intermediates covalently attached.