The Dos Family of Globin-Related Sensors Using PAS Domains to Accommodate Haem Acting as the Active Site for Sensing External Signals - Advances in Microbial Physiology - page 308

Figure 7.9 Crystal structure of the Aer2 N-terminal domain contains three successive
and interwoven HAMP domains. Ribbon representation of the Aer2 (1 - 172) dimer with
HAMP1 (AS1, light blue; AS2, blue), HAMP2 (AS1, orange; AS2, yellow), and HAMP3 (AS1,
light purple; AS2, purple). HAMP2/3 forms a concatenated structure. AS2 of HAMP1 is
contiguous with AS1 of HAMP2, and AS2 of HAMP2 is contiguous with AS1 of HAMP3.
HAMP3 is rotated roughly 90 relative to HAMP1 and HAMP2. Reproduced with permis-
sion from Airola et al. (2010) .
Figure 7.10 Crystal structure of PH-Aer2 consisting of the PAS and di-HAMP (residues
173 - 384) domains in the CN -bound form. The region from 307 to 384 is disordered.