Figure 1.

Interesting structural similarities between SERCA2b and Na⁺/K⁺-ATPase. (A) The PLN NMR structure (Seidel et al. 2008) and the carboxyl terminus of SERCA2b (Vandecaetsbeek et al. 2009b) modeled on the E2 crystal structure of rabbit SERCA1a (2AGV) (Obara et al. 2005). (B) Crystal structure of the pig renal Na⁺/K⁺-ATPase α-subunit (2ZXE) (Shinoda et al. 2009) in the E2 conformation, together with its regulatory β- and γ-subunits. Interesting similarities exist between the binding sites of the regulatory β- and γ-subunits on the Na⁺/K⁺-ATPase and, respectively, the 2b-tail and PLN on the SERCA1a pump. Orange: A-domain; Blue: P-domain; Green: N-domain; Gray: TM-domain. PLN, phospholamban; SLN, sarcolipin; 2b-tail, SERCA2b carboxyl terminus.