Project description:We used microarrays to analyze the effects of the disruption of mucR in planktonic S. meliloti strain Rm8530. S. meliloti were grown in minimal low-phosphate media to OD600 = 1.2 for RNA extraction and hybridization on Affymetrix microarrays.
Project description:The Alphaproteobacterium Sinorhizobium meliloti lives in soil and is capable of fixing molecular nitrogen in symbiosis with legume plants. In this work, the small proteome of S. meliloti strain 2011 was studied to uncover translation of both annotated and novel small open reading frame (sORF)-encoded proteins (SEPs).
Project description:We characterized transcriptomes of a Sinorhizobium meliloti wild type strain (CL150) expressing either Ca. Liberibacter asiaticus ctrA or Sinorhizobium meliloti ctrA
Project description:Hfq-dependent transcriptional alterations in the nitrogen-fixing endosymbiont S. meliloti. Comparison: S. meliloti 1021 strain Vs S. meliloti 1021Dhfq (containing a deletion of the hfq ORF).
Project description:Investigation of whole genome gene expression level changes in a Sinorhizobium meliloti 1021 rpoH1 rpoH2 double mutant, compared to the wild-type strain. The mutations engineered into this strain render it deficient in symbiotic nitrogen fixation. The mutants analyzed in this study are further described in Mitsui, H, T. Sato, Y. Sato, and K. Minamisawa. 2004. Sinorhizobium meliloti RpoH1 is required for effective nitrogen-fixing symbiosis with alfalfa. Mol Gen Genomics 271:416-425.
Project description:Sinorhizobium meliloti, a facultative microsymbiont of alfalfa, should fine-tune its cellular processes to live saprophytically in soils characterized with limited nutrients and diverse stresses. In this study, TiO2 enrichment and LC-MS/MS were used to uncover the site-specific Ser/Thr/Tyr phosphoproteome of S. meliloti in minimum medium at stationary phase. There are a total of 96 unique phosphorylated sites, with a Ser/Thr/Tyr distribution of 65:32:5, in 78 proteins. Phosphoproteins identified in S. meliloti showed a wide distribution pattern regarding to functional categories, such as replication, transcription, translation, posttranslational modification, transport and metabolism of amino acids, carbohydrate, inorganic ion, succinoglycan etc. Ser/Thr/Tyr phosphosites identified within the conserved motif in proteins of key cellular function indicate a crucial role of phosphorylation in modulating cellular physiology. Moreover, phosphorylation events potentially involved in rhizobial adaptation to diverse stresses were also discussed, such as those identified in SMa0114 and PhaP2 (polyhydroxybutyrate synthesis), ActR (pH stress and microaerobic adaption), SupA (potassium stress), chaperonin GroEL2 (viability and potentially symbiosis), and ExoP (succinoglycan synthesis and secretion). These Ser/Thr/Tyr phosphosites identified herein would be helpful for our further investigation and understanding of the role of phosphorylation in rhizobial physiology.
Project description:We show that the RNA leves of many genes in the S. meliloti overexpressing strain (OE) 2011 (pRK-RcsR1) are more similar to the levels of in wild type (WT) strain 2011 than in the empty vector control (EVC) strain 2011(pRK4352). Since the plasmid-containing strains were grown in the presence of 10 µg/ml tetracycline (Tc), while the WT was grown without Tc, the results suggest that the intrecellular Tc concentration in the OE strain are lower than in the EVC. This is explained by an increased efflux pump activity in the OE strain.