Premium
A strategy for the identification of protein architectures directly from ion mobility mass spectrometry data reveals stabilizing subunit interactions in light harvesting complexes
Author(s) -
Kaldmäe Margit,
Sahin Cagla,
Saluri Mihkel,
Marklund Erik G.,
Landreh Michael
Publication year - 2019
Publication title -
protein science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.353
H-Index - 175
eISSN - 1469-896X
pISSN - 0961-8368
DOI - 10.1002/pro.3609
Subject(s) - mass spectrometry , protein subunit , protein data bank (rcsb pdb) , protein data bank , chemistry , ion mobility spectrometry , cyanobacteria , biophysics , computational biology , biology , protein structure , crystallography , biochemistry , chromatography , bacteria , gene , genetics
Biotechnological applications of protein complexes require detailed information about their structure and composition, which can be challenging to obtain for proteins from natural sources. Prominent examples are the ring‐shaped phycoerythrin (PE) and phycocyanin (PC) complexes isolated from the light‐harvesting antennae of red algae and cyanobacteria. Despite their widespread use as fluorescent probes in biotechnology and medicine, the structures and interactions of their noncrystallizable central subunits are largely unknown. Here, we employ ion mobility mass spectrometry to reveal varying stabilities of the PC and PE complexes and identify their closest architectural homologues among all protein assemblies in the Protein Data Bank (PDB). Our results suggest that the central subunits of PC and PE complexes, although absent from the crystal structures, may be crucial for their stability, and thus of unexpected importance for their biotechnological applications.