FIG. 6.

Detection of c-di-GMP in nucleotide extracts from Y. pestis by HPLC analysis. An overlay of the A₂₅₄ curves from reverse-phase HPLC analysis of extracts from Y. pestis KIM6-2051(pBR322)+ and Y. pestis KIM6-2051(pAHMS16.1)+ grown in PMH2 medium at 26°C overnight in a shaken culture is shown. The peak at 18.9 min represents c-di-GMP, as determined from its correspondence to the retention time of synthetic c-di-GMP and by MALDI-TOF analysis (data not shown). This representative run used 10 times more sample than usual for the determination of cyclic di-GMP. Vector control, dashed line; HmsT⁺, solid line.