5VEG

Structure of a Short-Chain Flavodoxin Associated with a Non-Canonical PDU Bacterial Microcompartment

Summary for 5VEG

• Entry DOI: 10.2210/pdb5veg/pdb
• Descriptor: Flavodoxin, FLAVIN MONONUCLEOTIDE, CADMIUM ION, ... (5 entities in total)
• Functional Keywords: flavodoxin, bacterial microcompartments, electron transport
• Biological source: Lactobacillus reuteri
• Total number of polymer chains: 3
• Total formula weight: 59787.34

Authors

Sutter, M.,Plegaria, J.S.,Kerfeld, C.A. (deposition date: 2017-04-04, release date: 2017-10-11, Last modification date: 2023-10-04)

Primary citation

Plegaria, J.S.,Sutter, M.,Ferlez, B.,Aussignargues, C.,Niklas, J.,Poluektov, O.G.,Fromwiller, C.,TerAvest, M.,Utschig, L.M.,Tiede, D.M.,Kerfeld, C.A.
Structural and Functional Characterization of a Short-Chain Flavodoxin Associated with a Noncanonical 1,2-Propanediol Utilization Bacterial Microcompartment.
Biochemistry, 56:5679-5690, 2017

PubMed Abstract: Bacterial microcompartments (BMCs) are proteinaceous organelles that encapsulate enzymes involved in CO fixation (carboxysomes) or carbon catabolism (metabolosomes). Metabolosomes share a common core of enzymes and a distinct signature enzyme for substrate degradation that defines the function of the BMC (e.g., propanediol or ethanolamine utilization BMCs, or glycyl-radical enzyme microcompartments). Loci encoding metabolosomes also typically contain genes for proteins that support organelle function, such as regulation, transport of substrate, and cofactor (e.g., vitamin B) synthesis and recycling. Flavoproteins are frequently among these ancillary gene products, suggesting that these redox active proteins play an undetermined function in many metabolosomes. Here, we report the first characterization of a BMC-associated flavodoxin (Fld1C), a small flavoprotein, derived from the noncanonical 1,2-propanediol utilization BMC locus (PDU1C) of Lactobacillus reuteri. The 2.0 Å X-ray structure of Fld1C displays the α/β flavodoxin fold, which noncovalently binds a single flavin mononucleotide molecule. Fld1C is a short-chain flavodoxin with redox potentials of -240 ± 3 mV oxidized/semiquinone and -344 ± 1 mV semiquinone/hydroquinone versus the standard hydrogen electrode at pH 7.5. It can participate in an electron transfer reaction with a photoreductant to form a stable semiquinone species. Collectively, our structural and functional results suggest that PDU1C BMCs encapsulate Fld1C to store and transfer electrons for the reactivation and/or recycling of the B cofactor utilized by the signature enzyme.

PubMed: 28956602
DOI: 10.1021/acs.biochem.7b00682

Experimental method

X-RAY DIFFRACTION (1.99 Å)