Outer membrane cobalamin transporter (BTUB) from E. Coli, with bound calcium and cyanocobalamin (vitamin B12) substrate. Determined by X-ray diffraction at 3.1 Å resolution. Released 29 Apr 2003.
Explore 1NQH in 3D Show helices and sheets RCSB PDB PDBe
1NQH contains 9 α-helices and 34 β-strands across 1 chain. Residue ranges use author residue numbering, as in the PDB file, from PDBe. To see them in 3D, choose the Cartoon representation with Secondary structure coloring: helices, sheets and coils get different colors.
| Element | Residues | Length | Sheet |
|---|---|---|---|
| α-helix | 19-21 | 3 | |
| β-strand | 26-30 | 5 | 1 |
| α-helix | 31-37 | 7 | |
| α-helix | 42-46 | 5 | |
| β-strand | 54-56 | 3 | 2 |
| β-strand | 64-66 | 3 | 2 |
| α-helix | 68-70 | 3 | |
| β-strand | 77-80 | 4 | 1 |
| β-strand | 83-84 | 2 | 1 |
| α-helix | 101-103 | 3 | |
| β-strand | 106-111 | 6 | 1 |
| α-helix | 115-118 | 4 | |
| β-strand | 125-130 | 6 | 1 |
| β-strand | 137-145 | 9 | 3 |
| β-strand | 149-159 | 11 | 3 |
| β-strand | 164-175 | 12 | 3 |
| β-strand | 181 | 1 | 4 |
| β-strand | 197-209 | 13 | 3 |
| β-strand | 214-228 | 15 | 3 |
| β-strand | 242-257 | 16 | 3 |
| β-strand | 261-277 | 17 | 3 |
| β-strand | 289-305 | 17 | 3 |
| β-strand | 309-323 | 15 | 3 |
| β-strand | 334-348 | 15 | 3 |
| β-strand | 351-362 | 12 | 3 |
| β-strand | 366-380 | 15 | 3 |
| β-strand | 383-394 | 12 | 3 |
| α-helix | 398-402 | 5 | |
| β-strand | 413-426 | 14 | 3 |
| β-strand | 429-447 | 19 | 3 |
| α-helix | 448-450 | 3 | |
| β-strand | 452-471 | 20 | 3 |
| β-strand | 475-488 | 14 | 3 |
| β-strand | 494 | 1 | 3 |
| β-strand | 501-510 | 10 | 3 |
| β-strand | 515-523 | 9 | 3 |
| β-strand | 527-529 | 3 | 5 |
| α-helix | 536-537 | 2 | |
| β-strand | 538-540 | 3 | 5 |
| β-strand | 544-554 | 11 | 3 |
| β-strand | 559-566 | 8 | 3 |
| β-strand | 579 | 1 | 4 |
| β-strand | 585-593 | 9 | 3 |
| Molecule | Chains | Type | Length | Organism | UniProt |
|---|---|---|---|---|---|
| Vitamin B12 receptor | A | protein | 594 | Escherichia coli | P06129 (AlphaFold model) |
>1NQH_1 VITAMIN B12 RECEPTOR (chains A) QDTSPDTLVVTANRFEQPRSTVLAPTTVVTRQDIDRWQSTSVNDVLRRLPGVDITQNGGS GQLSSIFIRGTNASHVLVLIDGVRLNLAGVSGSADLSQFPIALVQRVEYIRGPRSAVYGS DAIGGVVNIITTRDEPGTEISAGWGSNSYQNYDVSTQQQLGDKTRVTLLGDYAHTHGYDV VAYGNTGTQAQTDNDGFLSKTLYGALEHNFTDAWSGFVRGYGYDNRTNYDAYYSPGSPLL DTRKLYSQSWDAGLRYNGELIKSQLITSYSHSKDYNYDPHYGRYDSSATLDEMKQYTVQW ANNVIVGHGSIGAGVDWQKQTTTPGTGYVEDGYDQRNTGIYLTGLQQVGDFTFEGAARSD DNSQFGRHGTWQTSAGWEFIEGYRFIASYGTSYKAPNLGQLYGFYGNPNLDPEKSKQWEG AFEGLTAGVNWRISGYRNDVSDLIDYDDHTLKYYNEGKARIKGVEATANFDTGPLTHTVS YDYVDARNAITDTPLLRRAKQQVKYQLDWQLYDFDWGITYQYLGTRYDKDYSSYPYQTVK MGGVSLWDLAVAYPVTSHLTVRGKIANLFDKDYETVYGYQTAGREYTLSGSYTF
| ID | Name | Formula | Copies |
|---|---|---|---|
| CA | Calcium ion | Ca | 4 |
| C8E | (hydroxyethyloxy)tri(ethyloxy)octane | C16 H34 O5 | 6 |
| CNC | Cyanocobalamin | C63 H89 Co N14 O14 P | 1 |
Substrate-induced transmembrane signaling in the cobalamin transporter BtuB. CHIMENTO, D.P., MOHANTY, A.K., KADNER, R.J. et al. Nat Struct Biol (2003) 10:394-401. DOI 10.1038/nsb914 · PubMed
Other PDB entries of the same protein (UniProt P06129 (AlphaFold model), which also has an AlphaFold model), best resolution first:
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