TY - JOUR
T1 - Methyl-dependent and spatial-specific DNA recognition by the orthologous transcription factors human AP-1 and Epstein-Barr virus Zta
AU - Hong, Samuel
AU - Wang, Dongxue
AU - Horton, John R.
AU - Zhang, Xing
AU - Speck, Samuel H.
AU - Blumenthal, Robert M.
AU - Cheng, Xiaodong
N1 - Funding Information:
National Institutes of Health (NIH) [GM049245-23 to X.C.]; Georgia Research Alliance Eminent Scholar [to X.C.]. The open access publication charge for this paper has been waived by Oxford University Press - NAR Editorial Board members are entitled to one free paper per year in recognition of their work on behalf of the journal.
Publisher Copyright:
© The Author(s) 2017.
PY - 2017/3/17
Y1 - 2017/3/17
N2 - Activator protein 1 (AP-1) is a transcription factor that recognizes two versions of a 7-base pair response element, either 5'-TGAGTCA-3' or 5'-MGAGTCA-3' (where M = 5-methylcytosine). These two elements share the feature that 5-methylcytosine and thymine both have a methyl group in the same position, 5- carbon of the pyrimidine, so each of them has two methyl groups at nucleotide positions 1 and 5 from the 5' end, resulting in four methyl groups symmetrically positioned in duplex DNA. Epstein-Barr Virus Zta is a key transcriptional regulator of the viral lytic cycle that is homologous to AP-1. Zta recognizes several methylated Zta-response elements, including meZRE1 (5'-TGAGMCA-3') and meZRE2 (5'- TGAGMGA-3'), where a methylated cytosine occupies one of the inner thymine residues corresponding to the AP-1 element, resulting in the four spatially equivalent methyl groups. Here, we study how AP-1 and Zta recognize these methyl groups within their cognate response elements. These methyl groups are in van der Waals contact with a conserved dialanine in AP-1 dimer (Ala265 and Ala266 in Jun), or with the corresponding Zta residues Ala185 and Ser186 (via its side chain carbon C' atom). Furthermore, the two ZRE elements differ at base pair 6 (C:G versus G:C), forming a pseudo-symmetric sequence (meZRE1) or an asymmetric sequence (meZRE2). In vitro DNA binding assays suggest that Zta has high affinity for all four sequences examined, whereas AP- 1 has considerably reduced affinity for the asymmetric sequence (meZRE2). We ascribe this difference to Zta Ser186 (a unique residue for Zta) whose side chain hydroxyl oxygen atom interacts with the two half sites differently, whereas the corresponding Ala266 of AP-1 Jun protein lacks such flexibility. Our analyses demonstrate a novel mechanism of 5mC/T recognition in a methylation-dependent, spatial and sequence-specific approach by basic leucine-zipper transcriptional factors.
AB - Activator protein 1 (AP-1) is a transcription factor that recognizes two versions of a 7-base pair response element, either 5'-TGAGTCA-3' or 5'-MGAGTCA-3' (where M = 5-methylcytosine). These two elements share the feature that 5-methylcytosine and thymine both have a methyl group in the same position, 5- carbon of the pyrimidine, so each of them has two methyl groups at nucleotide positions 1 and 5 from the 5' end, resulting in four methyl groups symmetrically positioned in duplex DNA. Epstein-Barr Virus Zta is a key transcriptional regulator of the viral lytic cycle that is homologous to AP-1. Zta recognizes several methylated Zta-response elements, including meZRE1 (5'-TGAGMCA-3') and meZRE2 (5'- TGAGMGA-3'), where a methylated cytosine occupies one of the inner thymine residues corresponding to the AP-1 element, resulting in the four spatially equivalent methyl groups. Here, we study how AP-1 and Zta recognize these methyl groups within their cognate response elements. These methyl groups are in van der Waals contact with a conserved dialanine in AP-1 dimer (Ala265 and Ala266 in Jun), or with the corresponding Zta residues Ala185 and Ser186 (via its side chain carbon C' atom). Furthermore, the two ZRE elements differ at base pair 6 (C:G versus G:C), forming a pseudo-symmetric sequence (meZRE1) or an asymmetric sequence (meZRE2). In vitro DNA binding assays suggest that Zta has high affinity for all four sequences examined, whereas AP- 1 has considerably reduced affinity for the asymmetric sequence (meZRE2). We ascribe this difference to Zta Ser186 (a unique residue for Zta) whose side chain hydroxyl oxygen atom interacts with the two half sites differently, whereas the corresponding Ala266 of AP-1 Jun protein lacks such flexibility. Our analyses demonstrate a novel mechanism of 5mC/T recognition in a methylation-dependent, spatial and sequence-specific approach by basic leucine-zipper transcriptional factors.
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U2 - 10.1093/nar/gkx057
DO - 10.1093/nar/gkx057
M3 - Article
C2 - 28158710
AN - SCOPUS:85018279534
SN - 0305-1048
VL - 45
SP - 2503
EP - 2515
JO - Nucleic acids research
JF - Nucleic acids research
IS - 5
ER -