7UNG

48-nm repeat of the human respiratory doublet microtubule

This is a non-PDB format compatible entry.

Summary for 7UNG

• Entry DOI: 10.2210/pdb7ung/pdb
• EMDB information: 26624
• Descriptor: Protein CFAP95, Meiosis-specific nuclear structural protein 1, Tektin-2, ... (38 entities in total)
• Functional Keywords: cilia, microtubule, sperm, cell motility, structural protein
• Biological source: Homo sapiens (human); More
• Total number of polymer chains: 435
• Total formula weight: 20589726.40

Authors

Gui, M.,Croft, J.T.,Zabeo, D.,Acharya, V.,Kollman, J.M.,Burgoyne, T.,Hoog, J.L.,Brown, A. (deposition date: 2022-04-11, release date: 2022-10-05, Last modification date: 2024-06-12)

Primary citation

Gui, M.,Croft, J.T.,Zabeo, D.,Acharya, V.,Kollman, J.M.,Burgoyne, T.,Hoog, J.L.,Brown, A.
SPACA9 is a lumenal protein of human ciliary singlet and doublet microtubules.
Proc.Natl.Acad.Sci.USA, 119:e2207605119-e2207605119, 2022

PubMed Abstract: The cilium-centrosome complex contains triplet, doublet, and singlet microtubules. The lumenal surfaces of each microtubule within this diverse array are decorated by microtubule inner proteins (MIPs). Here, we used single-particle cryo-electron microscopy methods to build atomic models of two types of human ciliary microtubule: the doublet microtubules of multiciliated respiratory cells and the distal singlet microtubules of monoflagellated human spermatozoa. We discover that SPACA9 is a polyspecific MIP capable of binding both microtubule types. SPACA9 forms intralumenal striations in the B tubule of respiratory doublet microtubules and noncontinuous spirals in sperm singlet microtubules. By acquiring new and reanalyzing previous cryo-electron tomography data, we show that SPACA9-like intralumenal striations are common features of different microtubule types in animal cilia. Our structures provide detailed references to help rationalize ciliopathy-causing mutations and position cryo-EM as a tool for the analysis of samples obtained directly from ciliopathy patients.

PubMed: 36191189
DOI: 10.1073/pnas.2207605119

Experimental method

ELECTRON MICROSCOPY (3.6 Å)