Rhizobium meliloti NodP and NodQ form a multifunctional sulfate-activating complex requiring GTP for activity.
The nodulation genes nodP and nodQ are required for production of Rhizobium meliloti nodulation (Nod) factors. These sulfated oligosaccharides act as morphogenic signals to alfalfa, the symbiotic host of R. meliloti. In previous work, we have shown that nodP and nodQ encode ATP sulfurylase, which catalyzes the formation of APS (adenosine 5'-phosphosulfate) and PPi. In the subsequent metabolic reaction, APS is converted to PAPS (3'-phosphoadenosine 5'-phosphosulfate) by APS kinase. In Escherichia coli, cysD and cysN encode ATP sulfurylase; cysC encodes APS kinase. Here, we present genetic, enzymatic, and sequence similarity data demonstrating that nodP and nodQ encode both ATP sulfurylase and APS kinase activities and that these enzymes associate into a multifunctional protein complex which we designate the sulfate activation complex. We have previously described the presence of a putative GTP-binding site in the nodQ sequence. The present report also demonstrates that GTP enhances the rate of PAPS synthesis from ATP and sulfate (SO4(2-)) by NodP and NodQ expressed in E. coli. Thus, GTP is implicated as a metabolic requirement for synthesis of the R. meliloti Nod factors.
Department of Biological Sciences, Stanford University, California 94305.
J S
JS
Schwedock
C
C
Liu
T S
TS
Leyh
S R
SR
Long
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D001483:Base Sequence; D003429:Cross Reactions; D004926:Escherichia coli / Q000235:genetics; D005816:Genetic Complementation Test; D006160:Guanosine Triphosphate / Q000378:metabolism; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes; D010724:Phosphoadenosine Phosphosulfate / Q000096:biosynthesis; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D016962:Sinorhizobium meliloti / Q000201:enzymology* / Q000235:genetics; D013430:Sulfate Adenylyltransferase / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D013431:Sulfates / Q000378:metabolism*; D013559:Symbiosis / Q000502:physiology
D001426:Bacterial Proteins; D009097:Multienzyme Complexes; D011994:Recombinant Proteins; D013431:Sulfates; C075085:nodP protein, Rhizobium; C075082:nodulation protein Q, Rhizobium; D010724:Phosphoadenosine Phosphosulfate; D006160:Guanosine Triphosphate; D017853:Phosphotransferases (Alcohol Group Acceptor); C019617:adenylylsulfate kinase; D013430:Sulfate Adenylyltransferase