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Carbonic anhydrase II: four measured distances from zinc

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The pinned RCSB PDB 3K34 coordinate file reports an X-ray structure at 0.90 Å resolution. Its header identifies human carbonic anhydrase II; the header describes a monomeric biological unit. The asymmetric unit has one coordinate chain. RCSB lists 1CA2 at 2.00 Å with water at the fourth zinc-site position; 3K34 gives a higher-resolution coordinate set with a recorded Zn–SUA N1 pair. The entry cites Behnke et al. (2010), PMID 20445237, DOI 10.1107/S0907444910006554. RCSB PDB 3K34; RCSB PDB 1CA2; primary paper, PMID 20445237.

Coordinate measurements

Each value is the Euclidean distance between the named heavy-atom positions in the pinned file. Values are rounded to two decimals; that arithmetic rounding does not imply experimental precision.

The third histidine endpoint is ND1 (His A 119), as recorded by the PDB LINK row; it is not an NE2 atom. The fourth selected pair reaches SUA A 1003 N1, a HETATM atom named in the PDB connection records. These are geometric measurements, not inferred bonds.

Diagram

Four dashed full three-dimensional heavy-atom distances from Zn A 1002 ZN to His A 94 NE2, His A 96 NE2, His A 119 ND1 and SUA A 1003 N1.
Dashed lines show measured heavy-atom distances; geometric, not bonds. The labels give full 3D values.

What the coordinate file records

For these four exact atom pairs, the file includes LINK rows and CONECT serial references. Those are deposited records, distinct from the distances computed from coordinates; they record the declared pairs without specifying a biological effect. The Zn, three histidines and SUA endpoints have occupancy 1.00. Their B-factors are listed with the measurements. This file has 2086 ATOM rows and 301 HETATM rows, including the Zn and SUA group; its HETATM records also include water and glycerol. It has 12 LINK, 63 CONECT and 13 SITE rows, one coordinate model, and 1 chain. Alternate locations occur elsewhere in the file; the diagram uses the blank/A conformer. No hydrogen/deuterium coordinate rows are present. A static coordinate model does not show motion or an event over time. RCSB PDB 3K34.

Video: fixed coordinates, rotating view

Heavy-atom distances are geometric measurements, not inferred bonds. Only the camera turns; no atom moves. Gold lines mark the four explicitly requested heavy-atom measurements. Green marks are automatic contact distances. The scene was checked against its native JSON; no atom moves.

Live: orbit it yourself

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See the measured diagram or video.

Heavy-atom distances are geometric measurements, not inferred bonds. A single static snapshot; no atom moves.

Papers the corpus links to this protein

The corpus links 118 papers across 1 UniProt entry (P00918); per-protein counts: P00918: 118. These papers are cross-referenced by the corpus and are not necessarily about this structure.

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