Figure 1

Amino acid sequence alignment of full-length Arabidopsis serpins. The alignment was created using ClustalW and edited. Locus numbers are given for some of the serpins. Amino acid residues are colour-coded: positively charged, blue; negatively charged, red; polar, green; cysteine, yellow; other residues, black. Dots above the alignment indicate residues identical in all six serpins. Putative positions of specific residues in the RCL are indicated below the alignment: P17 Glu, P8 Ser/Thr, P1 (shown in bold) and P4'. A gap, indicated by an arrow, between the P1 and P1' residues indicates the predicted site of proteinase cleavage. The predicted nuclear localization sequence for AtSRP3 is shown in bold italics. Large gaps in the sequences of the serpin at At1g62170, AtSRP2 and AtSRP3 (second block from bottom, right side) represent lack of a surface loop lying between helix I and strand 5 of β-sheet A (based on the human α₁-antitrypsin structure); absence of this loop is not expected to affect folding to a metastable structure capable of inhibiting proteinases [5].