DEMO-EM2: assembling protein complex structures from cryo-EM maps through intertwined chain and domain fitting.

Area of Science:

• Structural Biology
• Biophysics
• Computational Biology

Background:

• Cryo-electron microscopy (cryo-EM) yields increasing biological macromolecule density maps.
• Accurate atomic structure construction from cryo-EM maps, especially for protein complexes, remains a significant challenge.

Purpose of the Study:

• To present DEMO-EM2, an automated method for constructing protein complex atomic models from cryo-EM data.
• To improve the accuracy and efficiency of protein complex structure modeling.

Main Methods:

• DEMO-EM2 employs an iterative assembly procedure.
• It integrates chain- and domain-level matching and fitting for predicted chain models.
• The method was evaluated on cryo-electron tomography (cryo-ET) and single-particle EM maps.

Main Results:

• DEMO-EM2 models achieved an average TM-score of 0.92 across diverse cryo-EM datasets.
• The method demonstrated superior performance compared to existing state-of-the-art techniques.
• High accuracy was achieved for both cryo-ET and single-particle EM map modeling.

Conclusions:

• DEMO-EM2 provides an efficient and reliable solution for challenging cryo-EM structure modeling.
• The method facilitates rapid construction of accurate protein complex models.
• This work advances the field of structural biology by improving cryo-EM data interpretation.