2rix: Difference between revisions

From Proteopedia
Jump to navigationJump to search
← Older editNewer edit →
OCA (talk | contribs)
Bots, Bureaucrats, journal, Administrators
3,328,572 edits
No edit summary
OCA (talk | contribs)
Bots, Bureaucrats, journal, Administrators
3,328,572 edits
No edit summary
Line 1: Line 1:
[[Image:2rix.jpg|left|200px]]
{{Seed}}
[[Image:2rix.png|left|200px]]


<!--
<!--
Line 9: Line 10:
{{STRUCTURE_2rix|  PDB=2rix  |  SCENE=  }}  
{{STRUCTURE_2rix|  PDB=2rix  |  SCENE=  }}  


'''B-specific-1,3-galactosyltransferase)(GTB) + UDP'''
===B-specific-1,3-galactosyltransferase)(GTB) + UDP===




==Overview==
<!--
The final step in the enzymatic synthesis of the ABO(H) blood group A and B antigens is catalyzed by two closely related glycosyltransferases, an a-(1-3)-N-acetylgalactosaminyltransferase (GTA) and an a-(1-3)-galactosyltransferase (GTB). Of their 354 amino acid residues, GTA and GTB differ by only four 'critical' residues. High-resolution structures for GTB and the GTA/GTB chimeric enzymes GTB/G176R and GTB/G176R/G235S bound to a panel of donor and acceptor analog substrates reveal 'open', 'semi-closed' and 'closed' conformations as the enzymes go from the unliganded to the liganded states. In the 'open' form the internal polypeptide loop (amino acid residues 177-195) adjacent to the active site in the unliganded or H-antigen-bound enzymes is composed of two a-helices spanning Arg180-Met186 and Arg188-Asp194 respectively. The 'semi-closed' and closed forms of the enzymes are generated by binding of UDP or of UDP and H-antigen analogs respectively, and show that these helices merge to form a single distorted helical structure with alternating a-310-a character that partially occludes the active site. The 'closed' form is distinguished from the 'semi-closed' form by the ordering of the final nine C-terminal residues through the formation of hydrogen bonds to both UDP and H-antigen analogs. The 'semi-closed' forms for various mutants generally show significantly more disorder than the 'open' forms, while the 'closed' forms display little or no disorder depending strongly on the identity of residue 176. Finally, the use of synthetic analogs reveals how H-antigen acceptor binding can be critical in stabilizing the 'closed' conformation. These structures demonstrate a delicately-balanced substrate recognition mechanism and give insight on critical aspects of donor and acceptor specificity, on the order of substrate binding, and on the requirements for catalysis.
The line below this paragraph, {{ABSTRACT_PUBMED_18192272}}, adds the Publication Abstract to the page
(as it appears on PubMed at http://www.pubmed.gov), where 18192272 is the PubMed ID number.
-->
{{ABSTRACT_PUBMED_18192272}}


==Disease==
==Disease==
Line 41: Line 45:
[[Category: Transferase]]
[[Category: Transferase]]
[[Category: Transmembrane]]
[[Category: Transmembrane]]
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun May  4 16:59:49 2008''
 
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Tue Jul 29 11:56:00 2008''

Revision as of 08:56, 29 July 2008

File:2rix.png

Template:STRUCTURE 2rix

B-specific-1,3-galactosyltransferase)(GTB) + UDP

Template:ABSTRACT PUBMED 18192272

Disease

Known disease associated with this structure: Blood group, ABO system OMIM:[110300]

About this Structure

2RIX is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.

Reference

ABO(H) blood group A and B glycosyltransferases recognize substrate via specific conformational changes., Alfaro JA, Zheng RB, Persson M, Letts JA, Polakowski R, Bai Y, Borisova SN, Seto NO, Lowary TL, Palcic MM, Evans SV, J Biol Chem. 2008 Jan 11;. PMID:18192272

Page seeded by OCA on Tue Jul 29 11:56:00 2008

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "https://proteopedia.org/index.php?title=2rix&oldid=740110"