FIG. 3.

Signature sequence in Hsp70 proteins showing a specific relationship between archaebacteria (A) and gram-positive bacteria (G⁺) (both monoderm prokaryotes) and the distinctness of gram-negative bacteria (G⁻) (diderm prokaryotes). The large indel common in all gram-negative bacteria (referred to as the diderm insert) but absent in all monoderm prokaryotes is boxed. In the top diagram, 〉 denotes the root of the prokaryotic tree as inferred in the text. The thick arrow indicates the probable stage where this signature was introduced. The dashes in all sequence alignments show identity to the amino acids in the top line.