HNE modified amino acids identified in WRN. (A) Domain structure of the WRN protein. Positions of the HNE adducted amino acids are indicated by arrows. Functional domains are indicated below the structure. (B) Sequence alignment of WRN protein fragments (spanning part of the helicase and the C-terminus) of human, murine, horse, chicken (CHICK) and X. laevis (XENLA) origin. HNE modified amino acids, Lys577, Cys727, His1290, Cys1367, Lys1371 and Lys1389, are surrounded by red rectangles and indicated by arrows. Walker A motif (571–578) and nuclear localization sequence (1370–1375) are highlighted in yellow and dark blue rectangles, respectively. The peptides surrounding Lys577 are identically matched for seven residues toward the N-terminus and three residues toward the C-terminus. Human Lys577, Cys727, His1290, Cys1367, Lys1371 and Lys1389 correspond, respectively, to murine Lys541, Cys691, His1255, Cys1332, Arg1336 and Lys1354; horse Lys566, Cys716, His1280, Cys1359, Lys1363; chicken Lys556, Cys706, His1270, Cys1391, His1395 and Asp1438; and X. laevis Lys518, Cys668, His1238, Cys1348, Lys1352 and Thr1387. The picture was prepared with ClustalX2 (http://www.clustal.org) and visualized by Jalview (http://www.jalview.org).