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6mbk

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SETD3, a Histidine Methyltransferase, in Complex with an Actin Peptide and SAH, First P212121 Crystal Form

Structural highlights

6mbk is a 4 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 1.69Å
Ligands:	, , ,
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Disease

ACTB_HUMAN Defects in ACTB are a cause of dystonia juvenile-onset (DYTJ) [MIM:607371. DYTJ is a form of dystonia with juvenile onset. Dystonia is defined by the presence of sustained involuntary muscle contraction, often leading to abnormal postures. DYTJ patients manifest progressive, generalized, dopa-unresponsive dystonia, developmental malformations and sensory hearing loss.^[1] Defects in ACTB are the cause of Baraitser-Winter syndrome type 1 (BRWS1) [MIM:243310. A rare developmental disorder characterized by the combination of congenital ptosis, high-arched eyebrows, hypertelorism, ocular colobomata, and a brain malformation consisting of anterior-predominant lissencephaly. Other typical features include postnatal short stature and microcephaly, intellectual disability, seizures, and hearing loss.^[2]

Function

ACTB_HUMAN Actins are highly conserved proteins that are involved in various types of cell motility and are ubiquitously expressed in all eukaryotic cells.

Publication Abstract from PubMed

For more than 50 years, the methylation of mammalian actin at histidine 73 has been known to occur(1). Despite the pervasiveness of His73 methylation, which we find is conserved in several model animals and plants, its function remains unclear and the enzyme that generates this modification is unknown. Here we identify SET domain protein 3 (SETD3) as the physiological actin His73 methyltransferase. Structural studies reveal that an extensive network of interactions clamps the actin peptide onto the surface of SETD3 to orient His73 correctly within the catalytic pocket and to facilitate methyl transfer. His73 methylation reduces the nucleotide-exchange rate on actin monomers and modestly accelerates the assembly of actin filaments. Mice that lack SETD3 show complete loss of actin His73 methylation in several tissues, and quantitative proteomics analysis shows that actin His73 methylation is the only detectable physiological substrate of SETD3. SETD3-deficient female mice have severely decreased litter sizes owing to primary maternal dystocia that is refractory to ecbolic induction agents. Furthermore, depletion of SETD3 impairs signal-induced contraction in primary human uterine smooth muscle cells. Together, our results identify a mammalian histidine methyltransferase and uncover a pivotal role for SETD3 and actin His73 methylation in the regulation of smooth muscle contractility. Our data also support the broader hypothesis that protein histidine methylation acts as a common regulatory mechanism.

SETD3 is an actin histidine methyltransferase that prevents primary dystocia.,Wilkinson AW, Diep J, Dai S, Liu S, Ooi YS, Song D, Li TM, Horton JR, Zhang X, Liu C, Trivedi DV, Ruppel KM, Vilches-Moure JG, Casey KM, Mak J, Cowan T, Elias JE, Nagamine CM, Spudich JA, Cheng X, Carette JE, Gozani O Nature. 2019 Jan;565(7739):372-376. doi: 10.1038/s41586-018-0821-8. Epub 2018 Dec, 10. PMID:30626964^[3]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Procaccio V, Salazar G, Ono S, Styers ML, Gearing M, Davila A, Jimenez R, Juncos J, Gutekunst CA, Meroni G, Fontanella B, Sontag E, Sontag JM, Faundez V, Wainer BH. A mutation of beta -actin that alters depolymerization dynamics is associated with autosomal dominant developmental malformations, deafness, and dystonia. Am J Hum Genet. 2006 Jun;78(6):947-60. Epub 2006 Apr 21. PMID:16685646 doi:S0002-9297(07)63917-2
↑ Riviere JB, van Bon BW, Hoischen A, Kholmanskikh SS, O'Roak BJ, Gilissen C, Gijsen S, Sullivan CT, Christian SL, Abdul-Rahman OA, Atkin JF, Chassaing N, Drouin-Garraud V, Fry AE, Fryns JP, Gripp KW, Kempers M, Kleefstra T, Mancini GM, Nowaczyk MJ, van Ravenswaaij-Arts CM, Roscioli T, Marble M, Rosenfeld JA, Siu VM, de Vries BB, Shendure J, Verloes A, Veltman JA, Brunner HG, Ross ME, Pilz DT, Dobyns WB. De novo mutations in the actin genes ACTB and ACTG1 cause Baraitser-Winter syndrome. Nat Genet. 2012 Feb 26;44(4):440-4, S1-2. doi: 10.1038/ng.1091. PMID:22366783 doi:10.1038/ng.1091
↑ Wilkinson AW, Diep J, Dai S, Liu S, Ooi YS, Song D, Li TM, Horton JR, Zhang X, Liu C, Trivedi DV, Ruppel KM, Vilches-Moure JG, Casey KM, Mak J, Cowan T, Elias JE, Nagamine CM, Spudich JA, Cheng X, Carette JE, Gozani O. SETD3 is an actin histidine methyltransferase that prevents primary dystocia. Nature. 2019 Jan;565(7739):372-376. doi: 10.1038/s41586-018-0821-8. Epub 2018 Dec, 10. PMID:30626964 doi:http://dx.doi.org/10.1038/s41586-018-0821-8