1bwd: Difference between revisions

Revision as of 12:59, 21 February 2008

INOSAMINE-PHOSPHATE AMIDINOTRANSFERASE STRB1 FROM STREPTOMYCES GRISEUS

OverviewOverview

Inosamine-phosphate amidinotransferases catalyze two nonconsecutive transamidination reactions in the biosynthesis of the streptomycin family of antibiotics. L-Arginine:inosamine-phosphate amidinotransferase StrB1 from Streptomyces griseus (StrB1) was cloned as an N-terminal hexa-histidine fusion protein, purified by affinity chromatography, and crystallized, and its crystal structure was solved by Patterson search methods at 3.1 A resolution. The structure is composed of five betabeta alphabeta-modules which are arranged circularly into a pseudo-5-fold symmetric particle. The three-dimensional structure is closely related to the structure of human L-arginine:glycine amidinotransferase (AT), but five loops (the 40-, 170-, 220-, 250-, and 270-loop) are organized very differently. The major changes are found in loops around the active site which open the narrow active site channel of AT to form an open and solvent-exposed cavity. In particular, module II of StrB1 is AT-like but lacks a 10-residue alpha-helix in the 170-loop. The concomitant reorganization of neighboring surface loops that surround the active site, i.e., the 40-loop and the 270-loop, results in an arrangement of loops which allows an unrestricted access of substrates to the cavity. However, the residues which are involved in substrate binding and catalysis are conserved in AT and StrB1 and are at equivalent topological positions, suggesting a similar reaction mechanism among amidinotransferases. The binding site for L-arginine had been deduced from its complex with AT. Molecular modeling revealed a possible binding mode for the second substrate scyllo-inosamine 4-phosphate.

About this StructureAbout this Structure

1BWD is a Single protein structure of sequence from Streptomyces chryseus. Active as Scyllo-inosamine-4-phosphate amidinotransferase, with EC number 2.1.4.2 Full crystallographic information is available from OCA.

ReferenceReference

Crystal structure of L-arginine:inosamine-phosphate amidinotransferase StrB1 from Streptomyces griseus: an enzyme involved in streptomycin biosynthesis., Fritsche E, Bergner A, Humm A, Piepersberg W, Huber R, Biochemistry. 1998 Dec 22;37(51):17664-72. PMID:9922132

Page seeded by OCA on Thu Feb 21 11:59:53 2008

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

OCA

@@ Line 1: / Line 1: @@
-[[Image:1bwd.gif|left|200px]]<br /><applet load="1bwd" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1bwd.gif|left|200px]]<br /><applet load="1bwd" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1bwd, resolution 3.1&Aring;" />
 '''INOSAMINE-PHOSPHATE AMIDINOTRANSFERASE STRB1 FROM STREPTOMYCES GRISEUS'''<br />
 ==Overview==
-Inosamine-phosphate amidinotransferases catalyze two nonconsecutive, transamidination reactions in the biosynthesis of the streptomycin family, of antibiotics. L-Arginine:inosamine-phosphate amidinotransferase StrB1, from Streptomyces griseus (StrB1) was cloned as an N-terminal, hexa-histidine fusion protein, purified by affinity chromatography, and, crystallized, and its crystal structure was solved by Patterson search, methods at 3.1 A resolution. The structure is composed of five betabeta, alphabeta-modules which are arranged circularly into a pseudo-5-fold, symmetric particle. The three-dimensional structure is closely related to, the structure of human L-arginine:glycine amidinotransferase (AT), but, five loops (the 40-, 170-, 220-, 250-, and 270-loop) are organized very, differently. The major changes are found in loops around the active site, which open the narrow active site channel of AT to form an open and, solvent-exposed cavity. In particular, module II of StrB1 is AT-like but, lacks a 10-residue alpha-helix in the 170-loop. The concomitant, reorganization of neighboring surface loops that surround the active site, i.e., the 40-loop and the 270-loop, results in an arrangement of loops, which allows an unrestricted access of substrates to the cavity. However, the residues which are involved in substrate binding and catalysis are, conserved in AT and StrB1 and are at equivalent topological positions, suggesting a similar reaction mechanism among amidinotransferases. The, binding site for L-arginine had been deduced from its complex with AT., Molecular modeling revealed a possible binding mode for the second, substrate scyllo-inosamine 4-phosphate.
+Inosamine-phosphate amidinotransferases catalyze two nonconsecutive transamidination reactions in the biosynthesis of the streptomycin family of antibiotics. L-Arginine:inosamine-phosphate amidinotransferase StrB1 from Streptomyces griseus (StrB1) was cloned as an N-terminal hexa-histidine fusion protein, purified by affinity chromatography, and crystallized, and its crystal structure was solved by Patterson search methods at 3.1 A resolution. The structure is composed of five betabeta alphabeta-modules which are arranged circularly into a pseudo-5-fold symmetric particle. The three-dimensional structure is closely related to the structure of human L-arginine:glycine amidinotransferase (AT), but five loops (the 40-, 170-, 220-, 250-, and 270-loop) are organized very differently. The major changes are found in loops around the active site which open the narrow active site channel of AT to form an open and solvent-exposed cavity. In particular, module II of StrB1 is AT-like but lacks a 10-residue alpha-helix in the 170-loop. The concomitant reorganization of neighboring surface loops that surround the active site, i.e., the 40-loop and the 270-loop, results in an arrangement of loops which allows an unrestricted access of substrates to the cavity. However, the residues which are involved in substrate binding and catalysis are conserved in AT and StrB1 and are at equivalent topological positions, suggesting a similar reaction mechanism among amidinotransferases. The binding site for L-arginine had been deduced from its complex with AT. Molecular modeling revealed a possible binding mode for the second substrate scyllo-inosamine 4-phosphate.
 ==About this Structure==
-BWD is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Streptomyces_chryseus Streptomyces chryseus]. Active as [http://en.wikipedia.org/wiki/Scyllo-inosamine-4-phosphate_amidinotransferase Scyllo-inosamine-4-phosphate amidinotransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.1.4.2 2.1.4.2] Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1BWD OCA].
+BWD is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Streptomyces_chryseus Streptomyces chryseus]. Active as [http://en.wikipedia.org/wiki/Scyllo-inosamine-4-phosphate_amidinotransferase Scyllo-inosamine-4-phosphate amidinotransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.1.4.2 2.1.4.2] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1BWD OCA].
 ==Reference==
@@ Line 22: / Line 22: @@
 [[Category: streptomycin]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 11:58:15 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:59:53 2008''