Fig. 4: Structural analysis of SaSir2 ___domain and the assembly of the two-layered SaSir2 dodecamer. | Nature Communications

Fig. 4: Structural analysis of SaSir2 ___domain and the assembly of the two-layered SaSir2 dodecamer.

From: Mechanistic basis for the allosteric activation of NADase activity in the Sir2-HerA antiphage defense system

Fig. 4

a SaSir2 exhibits a typical Rossmann fold. b The closest structurally similar SaSir2 NADase (EcSir2, PDB 8SXX) to SaSir2. c Overlay of SaSir2 and EcSir2 highlighting the differences among SaSir2, EcSir2 and other Sir2 ___domain-containing proteins. The additional loop and α helix bundle are highlighted in blue. d Cartoon model of the SaSir2 dodecamer. e The hexameric layer of SaSir2 protomers that interact directly with SaHerA (upper layer). f The bottom layer of SaSir2 protomers that do not interact with SaHerA. g Homodimer units of SaSir2. h-i Enlarged view of the interactions shown in (g). j Neighboring SaSir2 dimer unit were pulled together by Sir2 molecules in the bottom layer (Molecule B) and the top layer (Molecule C). k Enlarged view of the β-hairpin formed in (j). l Detailed interactions of the interfaces shown in (j).

Back to article page