Table 1. Number of AOX′ and AOX positively selected sites that match bovine XDH protein-ligant contacts
2FeS, 19 FAD, 38 Mo, 9 Substrate, 10
AOX′ 1 (1.05) 8** (3.19) 1 (0.42) 3** (0.47)
AOX 0 (0.60) 12* (8.41) 4* (1.03) 6*** (1.15)
Identical matches 0 (0.00) 7** (2.50) 1 (0.30) 2 (0.30)
  • Numbers on the column headings are total predicted LPCs within the corresponding bovine XDH protein domains (after excluding 2FeS Asn-71, Mo Thr-1010, and Mo Val-1011 contacts because of alignment gaps; Mo and substrate ligands are in the Mo-pt domain); e.g., LPC software predicts 38 FAD-protein contacts within the FAD domain. In parentheses are the expected numbers of positively selected LPCs obtained assuming that the probability that a positively selected site match a LPC follows a binomial distribution. For AOX′ and AOX, the probability is obtained by dividing the number of positively selected sites in each domain (7, 22, and 28, and 4, 58, and 68 in the 2FeS, FAD, and Mo-pt domains, for AOX′ and AOX, respectively) by the length of the aligned domain (i.e., 127, 262, and 594 sites for 2FeS, FAD, and Mo-pt domains, respectively). For identical matches across AOX′ and AOX, the probability is obtained by dividing the number of positively selected sites matching LPCs (i.e., the values in the AOX′ and AOX rows of the table) by the total number of LPCs of each ligand. *, P < 0.05. **, P < 0.01. ***, P < 0.001.