The phenylpropeneoid uptake porter, CouPSTW. The purple photosynthetic bacterium Rhodopseudomonas palustris is able
to grow photoheterotrophically under anaerobic conditions on a range of
phenylpropeneoid lignin monomers, including coumarate, ferulate, caffeate, and cinnamate.
RPA1789 (CouP) is the periplasmic binding-protein component of the ABC uptake system (CouPSTU). CouP binds a range of
phenylpropeneoid ligands with Kd values in the nanomolar range. The
crystal structure of CouP with ferulate as the bound ligand shows H-bond
interactions between the 4-OH group of the aromatic ring with His309
and Gln305. H-bonds are also made between the carboxyl group on the
ferulate side chain and Arg197, Ser222, and Thr102 (Salmon et al. 2013). Within the same operon are a diguanylate cyclase (Q6N8W3) and a phenylacetate-CoA ligase (Q6N8W5).
|Protein Name:||Branched-chain amino acid transport system ATP-binding protein|
|Species:||Rhodopseudomonas palustris (strain ATCC BAA-98 / CGA009)  |
1: MTALLSVSGV SVSYGKVEAV RNVSLDVRQR EIVTVVGANG AGKTTLLSAA MGVLPLKGRV
61: TFDGIDVARL DIEDRVAAGL SLVPEHRELF ATMTVEDNLE LGAFRIAKAV AAQSQERVYG
121: LFPRLKERRK QLAGTLSGGE QQMLAMGRAL MGAPKLLMLD EPSLGLAPII VADIFRIVGE
181: LREAGVSVLL VEQNAKAALA IADRAYVMEL GEFVLDGPAS EVARNEAVVA SYLGFSHPA