ATP sulphurylase activity of the nodP and nodQ gene products of Rhizobium meliloti

Autor: Sharon R. Long, Julie Schwedock
Rok vydání: 1990
Předmět:
Zdroj: Nature. 348(6302)
ISSN: 0028-0836
Popis: THE symbiotic bacterium Rhizobium meliloti stimulates alfalfa (Medicago sativa L.) roots to undergo morphogenesis and form nitrogen-fixing nodules. It has been proposed that the bacterial genes nodABC, common to all Rhizobium, are required for synthesis of an oligosaccharide factor, which is converted to a sulphated form (NodRm-1) by the products of the R. meliloti-specific genes nodH and nodQ1–5; NodRm-1 elicits host-specific plant responses2. Previously we have shown that the nodP gene is homologous to a segment of the Escherichia coli genome6; when we cloned this E. coli fragment we found that it mapped near 59 minutes, corresponding to the cysDNC locus. The genes cysD and cysN encode proteins that catalyse the synthesis of adenosine 5′-phosphosulphate, the first step in the activation of inorganic sulphate7. Here we demonstrate that nodP and nodQ correspond to cysD and cysN, and that their proteins have ATP sulphurylase activity both in vivo and in vitro. We propose that nodP and nodQ synthesize an activated sulphate that is an intermediate in the formation of the alfalfa-specific sulphated nodRm-1 factor.
Databáze: OpenAIRE