Probing the Dual Role of Ca²⁺ in the <i>Allochromatium tepidum</i> LH1-RC Complex by Constructing and Analyzing Ca²⁺-Bound and Ca²⁺-Free LH1 Complexes.

ABSTRACT: The genome of the mildly thermophilic hot spring purple sulfur bacterium, Allochromatium (Alc.) tepidum, contains a multigene pufBA family that encodes a series of α- and β-polypeptides, collectively forming a heterogeneous light-harvesting 1 (LH1) complex. The Alc. tepidum LH1, therefore, offers a unique model for studying an intermediate phenotype between phototrophic thermophilic and mesophilic bacteria, particularly regarding their LH1 Qy transition and moderately enhanced thermal stability. Of the 16 α-polypeptides in the Alc. tepidum LH1, six α1 bind Ca²⁺ to connect with β1- or β3-polypeptides in specific Ca²⁺-binding sites. Here, we use the purple bacterium Rhodospirillum rubrum strain H2 as a host to expr

SUBMITTER: Zou MJ 

PROVIDER: S-EPMC11764377 | biostudies-literature | 2025 Jan

REPOSITORIES: biostudies-literature