Identification of chromophore binding domains of yeast DNA photolyase
Photolyases contain two chromophores, flavin plus either methenyltetrahydrofolate (MTHF) or 8-OH-5-deazaflavin (HDF). Amino acid sequence comparison reveals that all photolyases sequenced to date have extensive sequence homology in the carboxyl-terminal half; in the amino-terminal region the folate...
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Published in | The Journal of biological chemistry Vol. 267; no. 5; pp. 2909 - 2914 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
Bethesda, MD
American Society for Biochemistry and Molecular Biology
15.02.1992
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Subjects | |
Online Access | Get full text |
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Summary: | Photolyases contain two chromophores, flavin plus either methenyltetrahydrofolate (MTHF) or 8-OH-5-deazaflavin (HDF). Amino
acid sequence comparison reveals that all photolyases sequenced to date have extensive sequence homology in the carboxyl-terminal
half; in the amino-terminal region the folate and deazaflavin class enzymes are more homologous to other members of the same
class. This modular arrangement of sequence homologies suggests that the amino-terminal half of photolyase is involved in
MTHF or HDF binding whereas the carboxyl-terminal half carries the flavin binding site. In this study we attempted to identify
such structural domains of yeast photolyase by partial proteolysis and gene fusion techniques. Partial digestion with chymotrypsin
yielded an amino-terminal 34-kDa fragment containing tightly bound MTHF and a carboxyl-terminal 20-kDa polypeptide which lacked
chromophore or DNA binding activity. However, a fusion protein carrying the carboxyl-terminal 275 amino acids of yeast photolyase
bound specifically to FAD but not to MTHF or DNA. We conclude that the amino-terminal half of yeast photolyase constitutes
the folate binding domain and that the carboxyl-terminal half carries the flavin binding site. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 ObjectType-Article-1 ObjectType-Feature-2 |
ISSN: | 0021-9258 1083-351X |
DOI: | 10.1016/S0021-9258(19)50672-X |