Model-building pipeline in CCP-EM. For maps (or segments thereof) with resolutions of less than ∼5 Å and an appropriate model it is suggested to try DockEM followed by Flex-EM. For higher resolution data MOLREP and REFMAC can be used for refinement if a suitable model is available. If no model is available then Buccaneer can be used to build a model de novo. Note that for medium-resolution data sets a combination of approaches is recommended.