6mal

From Proteopedia

(Redirected from 6dip)

Structure of human Nocturnin C-terminal domain

Structural highlights

6mal is a 1 chain structure with sequence from Homo sapiens. This structure supersedes the now removed PDB entry 6dip. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 2.6Å
Ligands:
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

NOCT_HUMAN Circadian deadenylase which plays an important role in post-transcriptional regulation of metabolic genes under circadian control. Degrades poly(A) tails of specific target mRNAs leading to their degradation and suppression of translation. Exerts a rhythmic post-transcriptional control of genes necessary for metabolic functions including nutrient absorption, glucose/insulin sensitivity, lipid metabolism, adipogenesis, inflammation and osteogenesis. Plays an important role in favoring adipogenesis over osteoblastogenesis and acts as a key regulator of the adipogenesis/osteogenesis balance. Promotes adipogenesis by activating PPARG transcriptional activity in a deadenylase-independent manner by facilitating its nuclear translocation. Regulates circadian expression of NOS2 in the liver and negatively regulates the circadian expression of IGF1 in the bone. Critical for proper development of early embryos (By similarity).

Publication Abstract from PubMed

Nocturnin (NOCT) helps the circadian clock to adjust metabolism according to day and night activity. NOCT is upregulated in early evening and it has been proposed that NOCT serves as a deadenylase for metabolic enzyme mRNAs. We present a 2.7-A crystal structure of the catalytic domain of human NOCT. Our structure shows that NOCT has a close overall similarity to CCR4 deadenylase family members, PDE12 and CNOT6L, and to a DNA repair enzyme TDP2. All the key catalytic residues present in PDE12, CNOT6L and TDP2 are conserved in NOCT and have the same conformations. However, we observe substantial differences in the surface properties of NOCT, an unexpectedly narrow active site pocket, and conserved structural elements in the vicinity of the catalytic center, which are unique to NOCT and absent in the deadenylases PDE12/CNOT6L. Moreover, we show that in contrast to human PDE12 and CNOT6L, NOCT is completely inactive against poly-A RNA. Our work thus reveals the structure of an intriguing circadian protein and suggests that NOCT has considerable differences from the related deadenylases, which may point to a unique cellular function of this enzyme.

Crystal Structure of Human Nocturnin Catalytic Domain.,Estrella MA, Du J, Korennykh A Sci Rep. 2018 Nov 2;8(1):16294. doi: 10.1038/s41598-018-34615-0. PMID:30389976^[1]

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

References

↑ Estrella MA, Du J, Korennykh A. Crystal Structure of Human Nocturnin Catalytic Domain. Sci Rep. 2018 Nov 2;8(1):16294. doi: 10.1038/s41598-018-34615-0. PMID:30389976 doi:http://dx.doi.org/10.1038/s41598-018-34615-0