FIG. 3.

(A) Closed squares, relative amount of MCSPs following a cold shock from 30 to 10°C, as determined by 2D analysis. Inserts are examples of partial 2D gels. The two spots indicated by arrows include the MCSPs. Spot 1 contains CspA1 and CspB, and spot 2 contains CspA2 (22). Mean values and error bars are calculated from two to seven experiments. The maximum level of relative MCSP units per cell achieved in this experiment was set as 100%. Open circles, total MCSP amount per volume; the relative amount of MCSP was multiplied with the cell number (from Fig. 1A) to give a total MCSP amount of 1 culture volume [(MCSP units/cell) × (cells/milliliter)]. A horizontal course shows that the MCSPs are not degraded but are diluted due to cellular growth. A declining curve shows that MCSPs are additionally degraded. (B) The relative MCSP content determined by SDS-PAGE for the parental strain W 22703 (open diamonds) and the PNPase-deficient mutant strain YM 205 (closed circles) of Y. enterocolitica is shown. The maximum MCSP level achieved with the pnp mutant strain was set as 100%. The protein levels were measured only up to 270 min, and they decreased after this time, as shown by another experiment (data not shown).