Characterization of the substrate-binding PotD subunit in Synechocystis sp. strain PCC 6803

A1 Originalartikel i en vetenskaplig tidskrift (referentgranskad)


Interna författare/redaktörer


Publikationens författare: Anna-Maria Brandt, Wuttinun Raksajit, Panutda Yodsang, Paula Mulo, Aran Incharoensakdi, Tiina A. Salminen, Pirkko Mäenpää
Förläggare: SPRINGER
Publiceringsår: 2010
Tidskrift: Archives of Microbiology
Tidskriftsakronym: ARCH MICROBIOL
Volym: 192
Nummer: 10
Artikelns första sida, sidnummer: 791
Artikelns sista sida, sidnummer: 801
Antal sidor: 11
ISSN: 0302-8933


Abstrakt

The potD gene encodes the bacterial substrate-binding subunit of the polyamine transport system. The uptake system, which belongs to the ABC transporters, has been characterized in Escherichia coli, but it has not been previously studied in cyanobacteria. Although the overall sequence identity between Synechocystis sp. strain PCC 6803 (hereafter Synechocystis) PotD and Escherichia coli PotD is 24%, the ligand-binding site in the constructed homology model of Synechocystis PotD is well conserved. The conservation of the five polyamine-binding residues (Asp206, Glu209, Trp267, Trp293, and Asp295 in Synechocystis PotD) between these two species indicated polyamine-binding capacity for Synechocystis PotD. The Synechocystis potD gene is functional and its expression is under environmental regulation at transcriptional as well as post-transcriptional levels. Furthermore, an in vitro binding assay with the purified recombinant PotD protein demonstrated that the Synechocystis PotD protein is able to bind polyamines and favors spermidine over putrescine. Finally, we confirmed that Synechocystis PotD plays a physiological role in the uptake of polyamines in vivo using a constructed Synechocystis potD-disruption mutant.


Nyckelord

ABC transporter, Polyamine transport, PotD, Regulation of expression

Senast uppdaterad 2019-11-12 vid 01:52