Transcriptional activator protein Pur-alpha (PURA)

The protein contains 322 amino acids for an estimated molecular weight of 34911 Da.

 

This is a probable transcription activator that specifically binds the purine-rich single strand of the PUR element located upstream of the MYC gene. May play a role in the initiation of DNA replication and in recombination. (updated: April 1, 2015)

Protein identification was indicated in the following studies:

  1. Goodman and co-workers. (2013) The proteomics and interactomics of human erythrocytes. Exp Biol Med (Maywood) 238(5), 509-518.
  2. Lange and co-workers. (2014) Annotating N termini for the human proteome project: N termini and Nα-acetylation status differentiate stable cleaved protein species from degradation remnants in the human erythrocyte proteome. J Proteome Res. 13(4), 2028-2044.
  3. Hegedűs and co-workers. (2015) Inconsistencies in the red blood cell membrane proteome analysis: generation of a database for research and diagnostic applications. Database (Oxford) 1-8.
  4. Wilson and co-workers. (2016) Comparison of the Proteome of Adult and Cord Erythroid Cells, and Changes in the Proteome Following Reticulocyte Maturation. Mol Cell Proteomics. 15(6), 1938-1946.
  5. Bryk and co-workers. (2017) Quantitative Analysis of Human Red Blood Cell Proteome. J Proteome Res. 16(8), 2752-2761.
  6. D'Alessandro and co-workers. (2017) Red blood cell proteomics update: is there more to discover? Blood Transfus. 15(2), 182-187.
  7. Chu and co-workers. (2018) Quantitative mass spectrometry of human reticulocytes reveal proteome-wide modifications during maturation. Br J Haematol. 180(1), 118-133.

Methods

The following articles were analysed to gather the proteome content of erythrocytes.

The gene or protein list provided in the studies were processed using the ID mapping API of Uniprot in September 2018. The number of proteins identified and mapped without ambiguity in these studies is indicated below.
Only Swiss-Prot entries (reviewed) were considered for protein evidence assignation.

PublicationIdentification 1Uniprot mapping 2Not mapped /
Obsolete		TrEMBLSwiss-Prot
Goodman (2013)2289 (gene list)227853205992269
Lange (2014)123412347281224
Hegedus (2015)2638262202352387
Wilson (2016)165815281702911068
d'Alessandro (2017)18261817201815
Bryk (2017)20902060101081942
Chu (2018)18531804553621387

1 as available in the article and/or in supplementary material
2 uniprot mapping returns all protein isoforms as one entry

The compilation of older studies can be retrieved from the Red Blood Cell Collection database.

The data and differentiation stages presented below come from the proteomic study and analysis performed by our partners of the GReX consortium, more details are available in their published work.

No sequence conservation computed yet.
Protein sequence (FASTA)
Protein coevolution profile (FreeContact)
Multiple Sequence Alignment (Muscle)

Interpro domains
Total structural coverage: 46%
Model score: 0
No model available.

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VariantDescription
MRD31
MRD31
MRD31
MRD31
MRD31
MRD31

The reference OMIM entry for this protein is 600473

Purine-rich element-binding protein a; pura
Pur-alpha

DESCRIPTION

The PURA gene encodes a highly conserved protein with regulatory roles in DNA replication, gene transcription, RNA transport, and mRNA translation (summary by Hunt et al., 2014).

CLONING

Bergemann and Johnson (1992) characterized an approximately 28-kD protein from HeLa cell nuclear extracts that bound specifically to a purine-rich repeat element located at a site of DNA binding upstream of the human c-myc gene, and at origins of replication and transcription initiation sites in a variety of eukaryotes. Bergemann et al. (1992) cloned and sequenced the cDNA encoding this protein, designated PURA, from a human fetal liver cDNA library. The deduced 322-amino acid protein contains an N-terminal glycine-rich region, 3 repeats of a 23-amino acid class I motif, 2 repeats of a 26-amino acid class II motif, an amphipathic helix, and a C-terminal glutamine-glutamate-rich domain. Northern blot analysis of human fetal liver, HeLa cells, lung tumor cells, and hepatoma cells showed expression of 4 transcripts, from 2.0 to 5.0 kb, that are either multiple PURA transcripts or homologous mRNAs. RACE-PCR suggested the presence of 3 PURA transcripts of 1.6 to 2.1 kb. Kelm et al. (1997) cloned mouse Pura (p46) and Purb (p44) and identified them as the 2 components of the previously designated vascular actin single-stranded DNA-binding factor-2, which specifically bound to purine-rich regions within an enhancer and an exon of vascular actin (Kelm et al., 1996).

GENE FUNCTION

Bergemann et al. (1992) used gel shift assays to show that PURA binds preferentially to single-stranded DNA containing the purine-rich element. Pur-alpha is a single-stranded DNA-binding protein with specific affinity for a purine-rich element of the configuration (GGN)n present in several initiation zones of eukaryotic DNA replication. It interacts with large T-antigen and cellular protein YB-1 (154030) to activate JC viral DNA transcription in human cells (Chen et al., 1995). The functional activities of Pur-alpha, together with its evolutionary conservation, suggested that it may represent an important link between DNA replication and differential gene expression. Gallia et al. (2000) reviewed the structure and function of PURA. The central repeat region of PURA mediates binding to its single-stranded DNA target sequence as well as to regulatory proteins, both of which are modulated by RNA. In its C-terminal half, PURA contains an amphipathic alpha-helix with limited homology to the large tumor antigen of several polyomaviruses with a PSYC, or 'psycho,' motif. It also contains an N-terminal glycine-rich region. PURA is implicated in the transcriptional control of a number of cellular genes, including MBP (159430), FE65 (APBB1; 602709), and neuronal ACHR (e.g., CHRNB2; 118507), as well as viral promoters for JCV and HIV-1, which replicate in the central nervous system. PURA is also involved in the control of cell growth and interacts with the hypophosphorylated form of RB1 (614041). Fragile X-associated tremor/ataxia syndrome (FXTAS; 300623) is a neurodegenerative disorder caused by FMR1 premutation alleles containing 55 to 200 repeats of the trinucleotide CGG (309550.0004). Using gel-shift assays with mouse and fly brain lysates, followed by protein purification and mass spectroscopy, Jin et al. (2007) showed that Pur-alpha bound (CGG)105. Pur-alpha bound CGG repeats in a sequence-specific manner, and overexpression of Pur-alpha in a Droso ... More on the omim web site

Subscribe to this protein entry history

Feb. 2, 2018: Protein entry updated
Automatic update: Uniprot description updated

Dec. 19, 2017: Protein entry updated
Automatic update: Uniprot description updated

March 16, 2016: Protein entry updated
Automatic update: OMIM entry 600473 was added.