Alignment of the flexibility parameter between putative alkane hydroxylases in psychrophiles and mesophiles. Blue line indicates the difference in mean flexibility for the psychrophile and mesophile proteins, black line indicates the sum of the standard deviations for these two groups. Positive values for the mean (blue line) indicate positions in the alignment where the flexibility was greater for the psychrophile proteins; negative values, where flexibility was reduced. Gaps in the data reflect gaps in the alignment that prevented the calculation of the mean or standard deviation (SD). Center residues for windows with a significant increase in flexibility for psychrophiles and mesophiles are indicated by orange and green vertical dashed lines, respectively.