TY - JOUR
T1 - Structure of the monotopic membrane protein (S)-mandelate dehydrogenase at 2.2 Å resolution
AU - Sukumar, N.
AU - Liu, S.
AU - Li, W.
AU - Mathews, F. S.
AU - Mitra, B.
AU - Kandavelu, P.
N1 - Funding Information:
This work and the beamline NECAT 24IDE used to collect data are supported by award GM103403 from NIGMS of NIH and the NIH grant HL-121718 (WL). The Eiger 16 M detector on 24IDE beamline is funded by a NIH-ORIP HEI grant ( S10OD021527 ). We thank Professor Ealick, Cornell University and Dr. Bharat Reddy, University of Chicago for helpful discussions and Professor Perozo, University of Chicago for allowing us to use his lab facilities. Use of APS is supported by the U.S. DOE, office of Science and Contract No. DE-AC02-06CH11357 .
Funding Information:
This work and the beamline NECAT 24IDE used to collect data are supported by award GM103403 from NIGMS of NIH and the NIH grant HL-121718 (WL). The Eiger 16 M detector on 24IDE beamline is funded by a NIH-ORIP HEI grant (S10OD021527). We thank Professor Ealick, Cornell University and Dr. Bharat Reddy, University of Chicago for helpful discussions and Professor Perozo, University of Chicago for allowing us to use his lab facilities. Use of APS is supported by the U.S. DOE, office of Science and Contract No. DE-AC02-06CH11357.
Publisher Copyright:
© 2018 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM)
PY - 2018/11
Y1 - 2018/11
N2 - The x-ray structure of the monotopic membrane protein (S)-mandelate dehydrogenase (MDH) from Pseudomonas putida reveals an inherent flexibility of its membrane binding segment that might be important for its biological activity. The surface of MDH exhibits a concentration of the positive charges on one side and the negative charges on the other side. The putative membrane binding surface of MDH has a concentric circular ridge, formed by positively charged residues, which projects away from the protein surface by ∼4 Å; this is an unique structural feature and not observed in other monotopic membrane proteins to our knowledge. There are three α-helixes in the membrane binding region. Based on the structure of MDH, it is possible to propose that the interaction of MDH with the membrane is stabilized by coplanar electrostatic interactions, between the positively charged concentric circular ridge and the negatively charged head-groups of the phospholipid bilayer, along with three α-helixes that provide additional stability by inserting into the membrane. The structure reveals the possible orientation of these helixes along with possible roles for the individual residues which form those helixes. These α-helixes may play a role in the enzyme's mobility. A detergent molecule, N-Dodecyl-β-maltoside, is inserted between the membrane binding region and rest of the molecule and may provide structural stability to intra-protein regions by forming hydrogen bonds and close contacts. From the average B-factor of the MDH structure, it is likely that MDH is highly mobile, which might be essential for its interaction in membrane and non-membrane environments, as its substrate (S)-mandelate, is from the cytoplasm, while its electron acceptor is a component of the membrane electron transport chain.
AB - The x-ray structure of the monotopic membrane protein (S)-mandelate dehydrogenase (MDH) from Pseudomonas putida reveals an inherent flexibility of its membrane binding segment that might be important for its biological activity. The surface of MDH exhibits a concentration of the positive charges on one side and the negative charges on the other side. The putative membrane binding surface of MDH has a concentric circular ridge, formed by positively charged residues, which projects away from the protein surface by ∼4 Å; this is an unique structural feature and not observed in other monotopic membrane proteins to our knowledge. There are three α-helixes in the membrane binding region. Based on the structure of MDH, it is possible to propose that the interaction of MDH with the membrane is stabilized by coplanar electrostatic interactions, between the positively charged concentric circular ridge and the negatively charged head-groups of the phospholipid bilayer, along with three α-helixes that provide additional stability by inserting into the membrane. The structure reveals the possible orientation of these helixes along with possible roles for the individual residues which form those helixes. These α-helixes may play a role in the enzyme's mobility. A detergent molecule, N-Dodecyl-β-maltoside, is inserted between the membrane binding region and rest of the molecule and may provide structural stability to intra-protein regions by forming hydrogen bonds and close contacts. From the average B-factor of the MDH structure, it is likely that MDH is highly mobile, which might be essential for its interaction in membrane and non-membrane environments, as its substrate (S)-mandelate, is from the cytoplasm, while its electron acceptor is a component of the membrane electron transport chain.
KW - DDM
KW - FMN
KW - Membrane protein
KW - Monotopic
KW - X-ray
KW - α-hydroxy acid enzyme
UR - http://www.scopus.com/inward/record.url?scp=85050997333&partnerID=8YFLogxK
U2 - 10.1016/j.biochi.2018.07.017
DO - 10.1016/j.biochi.2018.07.017
M3 - Article
C2 - 30071260
AN - SCOPUS:85050997333
VL - 154
SP - 45
EP - 54
JO - Biochimie
JF - Biochimie
SN - 0300-9084
ER -