The Macromolecular Crystallographic Information File (mmCIF) also known as PDBx/mmCIF is a standard text file format for representing macromolecular structure data, developed by the

International Union of Crystallography The International Union of Crystallography (IUCr) is an organisation devoted to the international promotion and coordination of the science of crystallography. The IUCr is a member of the International Council for Science (ICSU). Objectives T ...

(IUCr) and the

Protein Data Bank The Protein Data Bank (PDB) is a database for the three-dimensional structural data of large biological molecules such as proteins and nucleic acids, which is overseen by the Worldwide Protein Data Bank (wwPDB). This structural data is obtained a ...

It is an extension of the

Crystallographic Information File Crystallographic Information File (CIF) is a standard text file format for representing crystallographic information, promulgated by the International Union of Crystallography (IUCr). CIF was developed by the IUCr Working Party on Crystallographi ...

(CIF), specifically for macromolecular data, such as proteins and nucleic acids, incorporating elements from the PDB file format. mmCIF is intended as an alternative to the Protein Data Bank (PDB) format and is now the default format used by the

. mmCIF was designed to address limitations of the PDB format in terms of capacity and flexibility, especially with the increasing size and complexity of macromolecular structures being determined. The format is part of the larger Crystallographic Information Framework, a system of exchange protocols based on data dictionaries and relational rules expressible in different machine-readable manifestations, including, but not restricted to, the original Crystallographic Information File and

XML Extensible Markup Language (XML) is a markup language and file format for storing, transmitting, and reconstructing data. It defines a set of rules for encoding electronic document, documents in a format that is both human-readable and Machine-r ...

Example

An example of the mmCIF file format is key-value style is:

_cell.entry_id           4HHB
_cell.length_a           63.150
_cell.length_b           83.590
_cell.length_c           53.800
_cell.angle_alpha        90.00
_cell.angle_beta         99.34
_cell.angle_gamma        90.00
_cell.Z_PDB              4

External links

International Union of Crystallography

wwPDB: mmCIF Resources

PDBx/mmCIF conversion service

References

Chemical file formats Computer file formats Crystallography Biological sequence format {{Crystallography-stub