9KIT | pdb_00009kit

Ni- Carbonic Anhydrase II pH 7.8 5.0 atm CO2

• PDB DOI: https://doi.org/10.2210/pdb9KIT/pdb

• Classification: METAL BINDING PROTEIN
• Organism(s): Homo sapiens
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 2024-11-11 Released: 2026-05-20 
• Deposition Author(s): Kim, C.U., Kim, J.K.
• Funding Organization(s): National Research Foundation (NRF, Korea)

---

Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.20 Å
• R-Value Free: 
  0.149 (Depositor), 0.155 (DCC) 
• R-Value Work: 
  0.124 (Depositor), 0.130 (DCC) 
• R-Value Observed: 
  0.125 (Depositor) 

Starting Model: experimental

Literature

Metal substituted Human Carbonic Anhydrase II under various CO2 pressure

Kim, C.U., Kim, J.K.

To be published.

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 assigned by authors and generated by PISA (software)

Biological Assembly Evidence: gel filtration

Macromolecule Content 

• Total Structure Weight: 29.56 kDa 
• Atom Count: 2,439 
• Modeled Residue Count: 257 
• Deposited Residue Count: 260 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Carbonic anhydrase 2	A	260	Homo sapiens	Mutation(s): 0  Gene Names: CA2 EC: 4.2.1.1 (PDB Primary Data), 4.2.1.69 (UniProt)
UniProt & NIH Common Fund Data Resources
Find proteins for P00918 (Homo sapiens) Explore P00918  Go to UniProtKB:  P00918
PHAROS:  P00918 GTEx:  ENSG00000104267

Small Molecules

Ligands 3 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
GOL	B [auth A]	GLYCEROL C3 H8 O3 PEDCQBHIVMGVHV-UHFFFAOYSA-N
BCT (Subject of Investigation/LOI)	E [auth A]	BICARBONATE ION C H O3 BVKZGUZCCUSVTD-UHFFFAOYSA-M
NI (Subject of Investigation/LOI)	C [auth A], D [auth A]	NICKEL (II) ION Ni VEQPNABPJHWNSG-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.20 Å
• R-Value Free:  0.149 (Depositor), 0.155 (DCC) 
• R-Value Work:  0.124 (Depositor), 0.130 (DCC) 
• R-Value Observed: 0.125 (Depositor) 

Space Group: P 1 2₁ 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 42.386	α = 90
b = 41.361	β = 104.07
c = 72.181	γ = 90

Software Package:

Software Name	Purpose
REFMAC	refinement
HKL-2000	data reduction
HKL-2000	data scaling
REFMAC	phasing

Structure Validation

Entry History 

& Funding Information

Deposition Data

• Released Date: 2026-05-20 
Deposition Author(s): Kim, C.U., Kim, J.K.

---

Funding Organization	Location	Grant Number
National Research Foundation (NRF, Korea)	Korea, Republic Of	NRF-2022R1A2C2091815

Revision History  

• Version 1.0: 2026-05-20
  Type: Initial release