Structures of mycobacterial 3-methylcrotonyl-CoA carboxylase reveal carrier-domain translocation between catalytic sites.

Authors

Ajit Yadav, Bogdan I Florea, Sebastian Geibel

Published in

FEBS letters. Sep 11, 2026. Epub Sep 11, 2026.

Abstract

3-Methylcrotonyl-CoA carboxylase (MCC) catalyzes an essential step in leucine degradation. Here, we report two high-resolution cryo-EM structures of endogenous, biotin-bound Mycobacterium smegmatis AccA1-AccD1 MCC. The α₆β₆ complex adopts a canonical architecture with a hexameric carboxyltransferase core flanked by trimeric biotin carboxylase modules. The structures capture BCCP engaged at either the BC or CT active site, revealing long-range carrier-domain translocation. In the CT-engaged state, local BC-domain shifts disrupt the BC-site BCCP-interaction network, disfavoring BCCP rebinding. Unlike human MCC, no comparable CT-core remodeling is observed, suggesting distinct mechanisms of carrier-domain coordination.

PMID:
42723463
Bibliographic data and abstract were imported from PubMed on 11 Sep 2026.

Read full publication at:
Please sign in to see all details.

Stats

1-terrible, 9-excellent. How would you rate this publication? Sign in in to submit your rating.

Post a comment

You need to be signed in to post comments. You can sign in here.

Comments

There are no comments yet.