Structural and Evolutionary Adaptation of NOD-Like Receptors in Birds

Figure 2

Sequence and primary functional differences in NLRC5 CARD are established (human, chicken, mouse, mammalian ancestor, and avian ancestor). (a) Sequence alignments of NLRC5 CARD domain. Adaptive amino acid substitutions in birds are represented with star (). Secondary structures of protein are shown along the top of the alignment. NLS (amino acids 121 to 134 in human) are shown. (b–e) The atypical CARD of NLRC5 consists of five α-helices (α1, α2, α4, α5, and α6) that are packed around a hydrophobic core. The CARD shape and electrostatic potential for human, chicken, mouse, mammalian ancestor, and avian ancestor are plotted. The surfaces are color-coded according to electrostatic surface potential: red, −10 kT; white, 0 kT; and blue, +10 kT. (f) Structural alignment of human, chicken, mammalian ancestor, and avian ancestor NLRC5 atypical CARD.

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