A Comprehensive Curation Shows the Dynamic Evolutionary Patterns of Prokaryotic CRISPRs

Table 1

Summary of CRISPR definitions in different studies.

# program	minDR #	minDR	maxDR	minSpacer	maxSpacer
CRT	3	19 bp	38 bp	19 bp	48 bp
CRISPRFinder	3	23 bp	55 bp	0.6 DR	2.5 DR
PILER-CR	3	16 bp	64 bp	8 bp	64 bp
caCRISPR	3	14 bp	55 bp	9 bp (0.3 DR)	95 bp (2.5 DR)

Column “minDR #” gives the minimum number of DRs required to define a CRISPR. Columns “minDR” and “maxDR” are the minimum and maximum DR lengths. The other two columns “minSpacer” and “maxSpacer” give the minimum and maximum spacer lengths for a CRISPR. The proposed definition for a CRISPR in this study is denoted as “caCRISPR,” and the other three computer programs compared in this study are CRT (CRISPR Recognition Tool) [7], CRISPRFinder [8], and PILER-CR [6].