東華大學圖書館 |

語系: 繁體中文

說明(常見問題)

回圖書館首頁

手機版館藏查詢

登入

回首頁

切換: 標籤 | MARC模式 | ISBD

Structural studies of type IA DNA to...

Changela, Anita.

FindBook

Google Book

Amazon

博客來

Structural studies of type IA DNA topoisomerases in complex with single-stranded DNA.

紀錄類型:	書目-語言資料,印刷品 : Monograph/item
正題名/作者:	Structural studies of type IA DNA topoisomerases in complex with single-stranded DNA./
作者:	Changela, Anita.
面頁冊數:	218 p.
附註:	Adviser: Alfonso Mondragon.
Contained By:	Dissertation Abstracts International63-04B.
標題:	Biophysics, General. -
電子資源:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3050501
ISBN:	0493649603

Structural studies of type IA DNA topoisomerases in complex with single-stranded DNA.
Changela, Anita.

Structural studies of type IA DNA topoisomerases in complex with single-stranded DNA. - 218 p.

Adviser: Alfonso Mondragon.

Thesis (Ph.D.)--Northwestern University, 2002.

DNA topoisomerases regulate DNA topology by transiently cleaving the phosphodiester backbone, allowing the passage of another DNA strand(s) through the break, and rejoining the broken DNA. Type IA topoisomerases cleave one strand of DNA via formation of a 5<super>′</super> covalent phosphotyrosine linkage. The crystal structures of two type IA enzymes from <italic>Escherichia coli</italic>, DNA topoisomerases I and III, have helped define a catalytic mechanism that explains how type IA topoisomerases can perform complex topological rearrangements of DNA. The proposed model emphasizes the need for type IA topoisomerases to recognize different DNA substrates using several distinct regions within the enzyme and to undergo various conformational changes in response to interactions with its substrate.

ISBN: 0493649603Subjects--Topical Terms:

1019105
Biophysics, General.

Structural studies of type IA DNA topoisomerases in complex with single-stranded DNA.
LDR:03436nam 2200301 a 45 001 935396
005 20110509
008 110509s2002 eng d
020 $a 0493649603
035 $a (UnM)AAI3050501
035 $a AAI3050501
040 $a UnM $c UnM
100 1 $a Changela, Anita. $3 1259085
245 1 0 $a Structural studies of type IA DNA topoisomerases in complex with single-stranded DNA.
300 $a 218 p.
500 $a Adviser: Alfonso Mondragon.
500 $a Source: Dissertation Abstracts International, Volume: 63-04, Section: B, page: 1822.
502 $a Thesis (Ph.D.)--Northwestern University, 2002.
520 $a DNA topoisomerases regulate DNA topology by transiently cleaving the phosphodiester backbone, allowing the passage of another DNA strand(s) through the break, and rejoining the broken DNA. Type IA topoisomerases cleave one strand of DNA via formation of a 5<super>′</super> covalent phosphotyrosine linkage. The crystal structures of two type IA enzymes from <italic>Escherichia coli</italic>, DNA topoisomerases I and III, have helped define a catalytic mechanism that explains how type IA topoisomerases can perform complex topological rearrangements of DNA. The proposed model emphasizes the need for type IA topoisomerases to recognize different DNA substrates using several distinct regions within the enzyme and to undergo various conformational changes in response to interactions with its substrate.
520 $a This thesis represents a structural investigation into the DNA binding behavior of type IA DNA topoisomerases. Nucleotide binding studies of the 67 kDa N-terminal fragment of <italic>E. coli</italic> topoisomerase I revealed several putative DNA binding sites within the enzyme and are discussed here. This thesis primarily describes the cocrystallization and three-dimensional structure determination of the wild type and inactive forms of <italic>E. coli</italic> DNA topoisomerase III in noncovalent complex with an 8-base single-stranded DNA molecule. The structures show the enzyme in different precleavage conformational states with the DNA either partially or fully-bound along a groove leading to the active site. In one conformation, a reorientation of domains has allowed for entrance of DNA into the active site where conserved residues have realigned in preparation for catalysis. These findings represent the first detailed look at a type IA DNA topoisomerase bound to its scissile DNA substrate while lending further insight into the catalytic mechanism and mode of ssDNA recognition used by these enzymes. Further characterization of the binding of <italic>E. coli</italic> DNA topoisomerase III to single-stranded DNA was carried out using fluorescence-based binding assays and preliminary results are presented.
520 $a In addition, a chapter in this thesis has been devoted to the crystallization and structure determination of the RNA triphosphatase component of mouse mRNA capping enzyme. Insights gained from this work provide a structural basis for understanding the function and catalytic mechanism of RNA triphosphatases belonging to the cysteine phosphatase superfamily of enzymes.
590 $a School code: 0163.
650 4 $a Biophysics, General. $3 1019105
650 4 $a Chemistry, Biochemistry. $3 1017722
690 $a 0487
690 $a 0786
710 2 0 $a Northwestern University. $3 1018161
773 0 $t Dissertation Abstracts International $g 63-04B.
790 $a 0163
790 1 0 $a Mondragon, Alfonso, $e advisor
791 $a Ph.D.
792 $a 2002
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3050501