Inhibited KdpFABC transitions into an E1 off-cycle state.

ABSTRACT: KdpFABC is a high-affinity prokaryotic K⁺ uptake system that forms a functional chimera between a channel-like subunit (KdpA) and a P-type ATPase (KdpB). At high K⁺ levels, KdpFABC needs to be inhibited to prevent excessive K⁺ accumulation to the point of toxicity. This is achieved by a phosphorylation of the serine residue in the TGES₁₆₂ motif in the A domain of the pump subunit KdpB (KdpB_S162-P). Here, we explore the structural basis of inhibition by KdpB_S162 phosphorylation by determining the conformational landscape of KdpFABC under inhibiting and non-inhibiting conditions. Under turnover conditions, we identified a new inhibited KdpFABC state that we termed E1P tight, which is not part of the canonical Post-Albers trans

SUBMITTER: Silberberg JM 

PROVIDER: S-EPMC9651954 | biostudies-literature | 2022 Oct

REPOSITORIES: biostudies-literature