This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.

Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.


3k3w

From Proteopedia

(Difference between revisions)
Jump to: navigation, search
Line 1: Line 1:
==Thermostable Penicillin G acylase from Alcaligenes faecalis in orthorhombic form==
==Thermostable Penicillin G acylase from Alcaligenes faecalis in orthorhombic form==
-
<StructureSection load='3k3w' size='340' side='right' caption='[[3k3w]], [[Resolution|resolution]] 3.31&Aring;' scene=''>
+
<StructureSection load='3k3w' size='340' side='right'caption='[[3k3w]], [[Resolution|resolution]] 3.31&Aring;' scene=''>
== Structural highlights ==
== Structural highlights ==
<table><tr><td colspan='2'>[[3k3w]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Alcfa Alcfa]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3K3W OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3K3W FirstGlance]. <br>
<table><tr><td colspan='2'>[[3k3w]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Alcfa Alcfa]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3K3W OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3K3W FirstGlance]. <br>
Line 21: Line 21:
<div style="background-color:#fffaf0;">
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
== Publication Abstract from PubMed ==
-
Penicillin amidase from Alcaligenes faecalis is a recently identified N-terminal nucleophile hydrolase, which possesses the highest specificity constant (kcat/Km) for the hydrolysis of benzylpenicillin compared with penicillin amidases from other sources. Similar to the Escherichia coli penicillin amidase, the A. faecalis penicillin amidase is maturated in vivo from an inactive precursor into the catalytically active enzyme, containing one tightly bound Ca2+ ion, via a complex post-translational autocatalytic processing with a multi-step excision of a small internal pro-peptide. The function of the pro-region is so far unknown. In vitro addition of chemically synthesized fragments of the pro-peptide to purified mature A. faecalis penicillin amidase increased its specific activity up to 2.3-fold. Mutations were used to block various steps in the proteolytic processing of the pro-peptide to obtain stable mutants with covalently attached fragments of the pro-region to their A-chains. These extensions of the A-chain raised the activity up to 2.3-fold and increased the specificity constants for benzylpenicillin hydrolysis mainly by an increase of the turnover number (kcat).
+
The enzyme penicillin G acylase (EC 3.5.1.11) catalyzes amide-bond cleavage in benzylpenicillin (penicillin G) to yield 6-aminopenicillanic acid, an intermediate chemical used in the production of semisynthetic penicillins. A thermostable penicillin G acylase from Alcaligenes faecalis (AfPGA) has been crystallized using the hanging-drop vapour-diffusion method in two different space groups: C222(1), with unit-cell parameters a = 72.9, b = 86.0, c = 260.2 , and P4(1)2(1)2, with unit-cell parameters a = b = 85.6, c = 298.8 . Data were collected at 293 and the structure was determined using the molecular-replacement method. Like other penicillin acylases, AfPGA belongs to the N-terminal nucleophilic hydrolase superfamily, has undergone post-translational processing and has a serine as the N-terminal residue of the beta-chain. A disulfide bridge has been identified in the structure that was not found in the other two known penicillin G cylase structures. The presence of the disulfide bridge is perceived to be one factor that confers higher stability to this enzyme.
-
Fragments of pro-peptide activate mature penicillin amidase of Alcaligenes faecalis.,Kasche V, Galunsky B, Ignatova Z Eur J Biochem. 2003 Dec;270(23):4721-8. PMID:14622260<ref>PMID:14622260</ref>
+
Crystallization and X-ray structure analysis of a thermostable penicillin G acylase from Alcaligenes faecalis.,Varshney NK, Kumar RS, Ignatova Z, Prabhune A, Pundle A, Dodson E, Suresh CG Acta Crystallogr Sect F Struct Biol Cryst Commun. 2012 Mar 1;68(Pt 3):273-7. Epub, 2012 Feb 15. PMID:22442220<ref>PMID:22442220</ref>
From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
Line 36: Line 36:
</StructureSection>
</StructureSection>
[[Category: Alcfa]]
[[Category: Alcfa]]
 +
[[Category: Large Structures]]
[[Category: Penicillin amidase]]
[[Category: Penicillin amidase]]
[[Category: Dodson, E]]
[[Category: Dodson, E]]

Revision as of 08:35, 1 January 2020

Thermostable Penicillin G acylase from Alcaligenes faecalis in orthorhombic form

PDB ID 3k3w

Drag the structure with the mouse to rotate

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/3k3w"
Personal tools