TY - JOUR
T1 - Fragile X repeats are potent inducers of complex, multiple site rearrangements in flanking sequences in Escherichia coli
AU - Kosmider, Beata
AU - Wells, Robert D.
PY - 2007/12/1
Y1 - 2007/12/1
N2 - (CGG·CCG)n repeats induce the formation of complex, multiple site rearrangements and/or gross deletions in flanking DNA sequences in Escherichia coli plasmids. DNA sequence analyses of mutant clones revealed the influence of (a) the length (24, 44 or 73 repeats), (b) the orientation of the CGG·CCG region relative to the unidirectional origin, and (c) its transcription status. Complex rearrangements had occurred in the mutant clones since some products contained deletions, inversions and insertions and some products had only gross deletions. Furthermore, the CGG·CCG repeats repeatedly induced, up to 22 times, the formation of identical (to the bp) mutagenic products indicating the powerful nature of the complex processes involved. Also, the mutations were bidirectional from the CGG·CCG tract. The healed junctions had CG-rich microhomologies of 1-6 bp, CG-rich regions and putative cruciforms and slipped structures. Hence, the fragile X syndrome mutagenic spectrum has been found, at least in part, in our model system.
AB - (CGG·CCG)n repeats induce the formation of complex, multiple site rearrangements and/or gross deletions in flanking DNA sequences in Escherichia coli plasmids. DNA sequence analyses of mutant clones revealed the influence of (a) the length (24, 44 or 73 repeats), (b) the orientation of the CGG·CCG region relative to the unidirectional origin, and (c) its transcription status. Complex rearrangements had occurred in the mutant clones since some products contained deletions, inversions and insertions and some products had only gross deletions. Furthermore, the CGG·CCG repeats repeatedly induced, up to 22 times, the formation of identical (to the bp) mutagenic products indicating the powerful nature of the complex processes involved. Also, the mutations were bidirectional from the CGG·CCG tract. The healed junctions had CG-rich microhomologies of 1-6 bp, CG-rich regions and putative cruciforms and slipped structures. Hence, the fragile X syndrome mutagenic spectrum has been found, at least in part, in our model system.
KW - CGG·CCG repeats
KW - Complex DNA rearrangements
KW - Gross deletions
KW - Non-B DNA structures
UR - http://www.scopus.com/inward/record.url?scp=35748933166&partnerID=8YFLogxK
U2 - 10.1016/j.dnarep.2007.07.014
DO - 10.1016/j.dnarep.2007.07.014
M3 - Article
C2 - 17851139
AN - SCOPUS:35748933166
SN - 1568-7864
VL - 6
SP - 1850
EP - 1863
JO - DNA Repair
JF - DNA Repair
IS - 12
ER -