Biomolecular complex, also called macromolecular complex or biomacromolecular complex, is any biological complex made of more than one molecule of protein, RNA, DNA, lipids, carbohydrates. The interactions between these biomolecules are non-covalent. Examples:
The biomacromolecular complexes are studied structurally by X-ray crystallography, NMR spectroscopy of proteins, cryo-electron microscopy and successive single particle analysis, and electron tomography. The atomic structure models obtained by X-ray crystallography and biomolecular NMR spectroscopy can be docked into the much larger structures of biomolecular complexes obtained by lower resolution techniques like electron microscopy, electron tomography, and small-angle X-ray scattering.