Cryo-EM structure of IrtAB in outward-occluded state in nanodisc in complex with ADP-vanadate

The mycobacterial ABC transporter IrtAB employs a membrane-facing crevice for siderophore-mediated iron uptake.

wild-type IrtAB in nanodisc in complex with ADP-orthovanadate in presence of 50uM MBT (unobserved)

Mycolicibacterium thermoresistibile ATCC 19527

micrographs were collected in super-resolution mode, 38 frames per movie

Sample was pre-incubated with 2.5mM ATP, 2.5mM Mg2+ ion and 5mM orthovanadate prior plunge-freezing. 50uM mycobactin substrate was added during nanodisc reconstitution.

Mycobactin import ATP-binding/permease protein IrtA

contains cleaved, C-terminal 3C enzyme recognition site
Mycobactin import ATP-binding/permease protein IrtB

SLRGLGARDHQATVVDKEYIAPHFVRVRLVSPTLFDEVIVEPTSWLRFWFPDPDGSDTEFQRAYTITESDPETGRFAVDM
VLHEPAGPASTWARTVEPGATIAVMSMGSRGFSVPEDPEDRPVGYLLIGDSASTPAINGIIEVVPHDIPIELYLEQHHDD
DVLIPLAEHPRLRVHRVSRDDASSLAAALELRDWSNWYCWAGPEAGALKQVRTRLRDEFGFPKREVYAQAYWTEGRAMGS
SRGETSTPAKPAAKTAPAKAAAKPAAASGAGTPEHAAAPAAATTGAPQAAPAPGAAQPRTPVRGRWRAEAGSRLLAPLKK
PLIVSGVLQALITLIELAPFVLLVELARLLLGGAEAERLWTLGLTAVSLIGLGAVLAAAMTLWLHRVDARFAHELRGRLL
TKLSRLPLGWFTRRGSASTKQLVQDDTLALHYLITHAIPDAVAAVVAPVAVLVYLFVADWRVALVLFIPVLVYLVLMSVM
TIQSGSKIAQAPRWAERMGGEAGAFLEGQPVIRIFGGAAASRFRRRLDDYIDFLVSWQRPFVGKKTLMDLVTRPATFLWI
ILVAGVPLVVTGRMDPVNLLPFLLLGTTFGARLLGIGYGLSGIQTGMLAARRIQTVLDEPELVVRDRTGQAGTDHASGDQ
ARPGTVELDRVSFEYRPGVPVIRDVTLTLRPGTVTALVGPSGSGKSTLAALVARFHDVTQGAIRVDGRDIRTLTADELYR
RVGFVLQDAQLVHGSVAENIALAEPDAGLERIRTAARDAQIHDRITRMPDGYDSVLGAGSALSGGERQRVTIARAILADT
PVLVLDEATAFADPESEYLVQQAINRLTRDRTVLVIAHRLHTITHADQIVVLDDGRIVEVGTHDELLAAGGRYRGLWDSG
RYSSPDAGRPVSADAVEVGR

MIRTLLRLVPAEKRGAVAGYAVLTLLSVLLRAVGAVLLIPLLAALFSDTPSDAWLWLGWLTAVTLAGWVTDTNTARLGFD
LGFAVLSRTQHDMADRLPNVAMSWFTPDNTATARQAIAATGPELAGLVVNLLTPLIGAALLPAAIGVALLFVSVPLGLAA
LAGVAVLFGALALSGRLSRAADKVAGETNSAFTERIIEFARTQQALRAARRVEPARSQVGSALAAQHGAGLRLLTMQIPG
QVLFSLAGQVALIGFAGMAVWLTVRGQLGVPEAIALIVVLVRYLEPFAAIADLAPALETTRATLNRIQAVLDAPTLPAGR
RRLDRTGAAPSIEFDDVRFSYGDEVVLDGVSFTLRPGNTTAIVGPSGSGKTTILSLIAGLQQPASGRVLLDGVDVTTLDP
EARRAAVSVVFQHPYLFDGTLRDNVLVGDPEADPDDVTAAMRLARVDELLDRLPDGDATVVGEGGTALSGGERQRVSIAR
ALLKPAPVLLVDEATSALDNANEAAVVDALTADPRPRTRVIVAHRLASIRHADRVLFVEAGRVVEDGAIDELLAAGGRFA
QFWAQQQAASEWAIGSTARALEVLFQ

ABC transporter, type IV ABC importer siderophore, mycobactin, heterodimeric ABC transporter, MEMBRANE PROTEIN

LRGLGARDHQATVVDKEYIAPHFVRVRLVSPTLFDEVIVEPTSWLRFWFPDPDGSDTEFQRAYTITESDPETGRFAVDMV
LHEPAGPASTWARTVEPGATIAVMSMGSRGFSVPEDPEDRPVGYLLIGDSASTPAINGIIEVVPHDIPIELYLEQHHDDD
VLIPLAEHPRLRVHRVSRDDASSLAAALELRDWSNWYCWAGPEAGALKQVRTRLRDEFGFPKREVYAQAYWTEGRAMGSS
RGETSTPAKPAAKTAPAKAAAKPAAASGAGTPEHAAAPAAATTGAPQAAPAPGAAQPRTPVRGRWRAEAGSRLLAPLKKP
LIVSGVLQALITLIELAPFVLLVELARLLLGGAEAERLWTLGLTAVSLIGLGAVLAAAMTLWLHRVDARFAHELRGRLLT
KLSRLPLGWFTRRGSASTKQLVQDDTLALHYLITHAIPDAVAAVVAPVAVLVYLFVADWRVALVLFIPVLVYLVLMSVMT
IQSGSKIAQAPRWAERMGGEAGAFLEGQPVIRIFGGAAASRFRRRLDDYIDFLVSWQRPFVGKKTLMDLVTRPATFLWII
LVAGVPLVVTGRMDPVNLLPFLLLGTTFGARLLGIGYGLSGIQTGMLAARRIQTVLDEPELVVRDRTGQAGTDHASGDQA
RPGTVELDRVSFEYRPGVPVIRDVTLTLRPGTVTALVGPSGSGKSTLAALVARFHDVTQGAIRVDGRDIRTLTADELYRR
VGFVLQDAQLVHGSVAENIALAEPDAGLERIRTAARDAQIHDRITRMPDGYDSVLGAGSALSGGERQRVTIARAILADTP
VLVLDEATAFADPESEYLVQQAINRLTRDRTVLVIAHRLHTITHADQIVVLDDGRIVEVGTHDELLAAGGRYRGLWDSGR
YSSPDAGRPVSADAVEVGR

MIRTLLRLVPAEKRGAVAGYAVLTLLSVLLRAVGAVLLIPLLAALFSDTPSDAWLWLGWLTAVTLAGWVTDTNTARLGFD
LGFAVLSRTQHDMADRLPNVAMSWFTPDNTATARQAIAATGPELAGLVVNLLTPLIGAALLPAAIGVALLFVSVPLGLAA
LAGVAVLFGALALSGRLSRAADKVAGETNSAFTERIIEFARTQQALRAARRVEPARSQVGSALAAQHGAGLRLLTMQIPG
QVLFSLAGQVALIGFAGMAVWLTVRGQLGVPEAIALIVVLVRYLEPFAAIADLAPALETTRATLNRIQAVLDAPTLPAGR
RRLDRTGAAPSIEFDDVRFSYGDEVVLDGVSFTLRPGNTTAIVGPSGSGKTTILSLIAGLQQPASGRVLLDGVDVTTLDP
EARRAAVSVVFQHPYLFDGTLRDNVLVGDPEADPDDVTAAMRLARVDELLDRLPDGDATVVGEGGTALSGGERQRVSIAR
ALLKPAPVLLVDEATSALDNANEAAVVDALTADPRPRTRVIVAHRLASIRHADRVLFVEAGRVVEDGAIDELLAAGGRFA
QFWAQQQAASEWAIGSTAR