EMD-26624
Composite cryo-EM density map of the 48-nm repeat of the human respiratory doublet microtubule
EMD-26624
Single-particle3.6 Å
![EMD-26624](/em_static/emdb/emdb_no_image.png)
Map released: 05/10/2022
Last modified: 12/06/2024
Sample Organism:
Homo sapiens
Sample: Doublet microtubule and associated proteins
Fitted models: 7ung
Deposition Authors: Gui M
,
Croft JT
,
Zabeo D
,
Acharya V,
Kollman JM,
Burgoyne T
,
Hoog JL
,
Brown A
Sample: Doublet microtubule and associated proteins
Fitted models: 7ung
Deposition Authors: Gui M
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SPACA9 is a lumenal protein of human ciliary singlet and doublet microtubules.
Gui M
,
Croft JT
,
Zabeo D
,
Acharya V,
Kollman JM,
Burgoyne T
,
Hoog JL
,
Brown A
(2022) PNAS , 119 , e2207605119 - e2207605119
![](http://www.ebi.ac.uk/web_guidelines/images/logos/orcid/orcid_16x16.png)
![](http://www.ebi.ac.uk/web_guidelines/images/logos/orcid/orcid_16x16.png)
![](http://www.ebi.ac.uk/web_guidelines/images/logos/orcid/orcid_16x16.png)
![](http://www.ebi.ac.uk/web_guidelines/images/logos/orcid/orcid_16x16.png)
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![](http://www.ebi.ac.uk/web_guidelines/images/logos/orcid/orcid_16x16.png)
(2022) PNAS , 119 , e2207605119 - e2207605119
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.
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.