Table 1.

Evolutionary conservation of D305 in PQ-loop motifs

Type of PQ-loop motif	Number of occurrences at position equivalent to D305
	any amino acid	D	E	D or E
Single PQ loop	125	5	33	38
First motif of pair	384	8	69	77
Second motif of pair	384	98	0	98
Both motifs of pair	384	0	0	0

PQ-loop sequences from 509 proteins found in diverse eukaryotes were downloaded from the SMART database (entry SM00679) and analyzed for the presence of an acidic residue at position +21 downstream the canonical PQ dipeptide.