2fz4: Difference between revisions

Line 4:

==Overview==

The human xeroderma pigmentosum group B (XPB) helicase is essential for, transcription, nucleotide excision repair, and TFIIH functional assembly., Here, we determined crystal structures of an Archaeoglobus fulgidus XPB, homolog (AfXPB) that characterize two RecA-like XPB helicase domains and, discover a DNA damage recognition domain (DRD), a unique RED motif, a, flexible thumb motif (ThM), and implied conformational changes within a, conserved functional core. RED motif mutations dramatically reduce, helicase activity, and the DRD and ThM, which flank the RED motif, appear, structurally as well as functionally analogous to the MutS mismatch, recognition and DNA polymerase thumb domains. Substrate specificity is, altered by DNA damage, such that AfXPB unwinds dsDNA with 3' extensions, but not blunt-ended dsDNA, unless it contains a lesion, as shown for CPD, or (6-4) photoproducts. Together, these results provide an unexpected, mechanism of DNA unwinding with implications for XPB damage verification, in nucleotide excision repair.

The human xeroderma pigmentosum group B (XPB) helicase is essential for transcription, nucleotide excision repair, and TFIIH functional assembly. Here, we determined crystal structures of an Archaeoglobus fulgidus XPB homolog (AfXPB) that characterize two RecA-like XPB helicase domains and discover a DNA damage recognition domain (DRD), a unique RED motif, a flexible thumb motif (ThM), and implied conformational changes within a conserved functional core. RED motif mutations dramatically reduce helicase activity, and the DRD and ThM, which flank the RED motif, appear structurally as well as functionally analogous to the MutS mismatch recognition and DNA polymerase thumb domains. Substrate specificity is altered by DNA damage, such that AfXPB unwinds dsDNA with 3' extensions, but not blunt-ended dsDNA, unless it contains a lesion, as shown for CPD or (6-4) photoproducts. Together, these results provide an unexpected mechanism of DNA unwinding with implications for XPB damage verification in nucleotide excision repair.

==About this Structure==

Line 14:

[[Category: Single protein]]

[[Category: Fan, L.]]

[[Category: Tainer, J.A.]]

[[Category: Tainer, J A.]]

[[Category: dna damage recognition domain]]

[[Category: reca-like domain]]

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on ~~Tue Jan 29 19~~:47:58 2008''

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:26:36 2008''

Navigation menu

Page actions

Page actions

Personal tools

Navigation

Search

Tools

@@ Line 4: / Line 4: @@
 ==Overview==
-The human xeroderma pigmentosum group B (XPB) helicase is essential for, transcription, nucleotide excision repair, and TFIIH functional assembly., Here, we determined crystal structures of an Archaeoglobus fulgidus XPB, homolog (AfXPB) that characterize two RecA-like XPB helicase domains and, discover a DNA damage recognition domain (DRD), a unique RED motif, a, flexible thumb motif (ThM), and implied conformational changes within a, conserved functional core. RED motif mutations dramatically reduce, helicase activity, and the DRD and ThM, which flank the RED motif, appear, structurally as well as functionally analogous to the MutS mismatch, recognition and DNA polymerase thumb domains. Substrate specificity is, altered by DNA damage, such that AfXPB unwinds dsDNA with 3' extensions, but not blunt-ended dsDNA, unless it contains a lesion, as shown for CPD, or (6-4) photoproducts. Together, these results provide an unexpected, mechanism of DNA unwinding with implications for XPB damage verification, in nucleotide excision repair.
+The human xeroderma pigmentosum group B (XPB) helicase is essential for transcription, nucleotide excision repair, and TFIIH functional assembly. Here, we determined crystal structures of an Archaeoglobus fulgidus XPB homolog (AfXPB) that characterize two RecA-like XPB helicase domains and discover a DNA damage recognition domain (DRD), a unique RED motif, a flexible thumb motif (ThM), and implied conformational changes within a conserved functional core. RED motif mutations dramatically reduce helicase activity, and the DRD and ThM, which flank the RED motif, appear structurally as well as functionally analogous to the MutS mismatch recognition and DNA polymerase thumb domains. Substrate specificity is altered by DNA damage, such that AfXPB unwinds dsDNA with 3' extensions, but not blunt-ended dsDNA, unless it contains a lesion, as shown for CPD or (6-4) photoproducts. Together, these results provide an unexpected mechanism of DNA unwinding with implications for XPB damage verification in nucleotide excision repair.
 ==About this Structure==
@@ Line 14: / Line 14: @@
 [[Category: Single protein]]
 [[Category: Fan, L.]]
-[[Category: Tainer, J.A.]]
+[[Category: Tainer, J A.]]
 [[Category: dna damage recognition domain]]
 [[Category: reca-like domain]]
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Tue Jan 29 19:47:58 2008''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:26:36 2008''