Sulfur Metabolism in Corynebacterium glutamicum
Christian Rückert and Jörn Kalinowski
from: Corynebacteria: Genomics and Molecular Biology (Edited by: Andreas Burkovski). Caister Academic Press, U.K. (2008)
Sulfur is an important element for life as it is a constituent of a number of essential organic molecules like cysteine, methionine, Coenzyme A, or iron sulfur clusters. In turn, these compounds are involved in a number of essential cellular processes like protein biosynthesis or the transfer of electrons and acyl groups. Yet, an external supply of these compounds is essential for many eucaryotes and, due to their scarcity in many foods and feeds, their biosynthesis is of great industrial interest. Therefore, the metabolism of sulfur in Corynebacterium glutamicum has been studied in more and more detail in recent years. Besides the pathways to obtain and utilize sulfur from the environment especially the reactions leading to and from the sulfur-containing amino acids cysteine and methionine have been analyzed in great detail, revealing a number of so far unique metabolic routes. In addition, the regulation of sulfur metabolism has been analyzed on the transcriptional as well as on the enzymatic level, revealing the presence of at least three transcriptional regulators and a high number of feed-back inhibitions of key enzymes. In this chapter, the current state of knowledge concerning the central pathways of sulfur metabolism (i.e. those consuming most of the cellular sulfur) is summarized and a short outlook on the perspectives to produce methionine and cysteine is given read more ...