6BYX

Complex structure of LOR107 mutant (R259N) with tetrasaccharide substrate


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.21 Å
  • R-Value Free: 0.255 
  • R-Value Work: 0.204 
  • R-Value Observed: 0.205 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Structure-function analyses of a PL24 family ulvan lyase reveal key features and suggest its catalytic mechanism.

Ulaganathan, T.Helbert, W.Kopel, M.Banin, E.Cygler, M.

(2018) J Biol Chem 293: 4026-4036

  • DOI: 10.1074/jbc.RA117.001642
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • Ulvan is a major cell wall component of green algae of the genus Ulva , and some marine bacteria encode enzymes that can degrade this polysaccharide. The first ulvan-degrading lyases have been recently characterized, and several putative ulva ...

    Ulvan is a major cell wall component of green algae of the genus Ulva , and some marine bacteria encode enzymes that can degrade this polysaccharide. The first ulvan-degrading lyases have been recently characterized, and several putative ulvan lyases have been recombinantly expressed, confirmed as ulvan lyases, and partially characterized. Two families of ulvan-degrading lyases, PL24 and PL25, have recently been established. The PL24 lyase LOR_107 from the bacterial Alteromonadales sp. strain LOR degrades ulvan endolytically, cleaving the bond at the C4 of a glucuronic acid. However, the mechanism and LOR_107 structural features involved are unknown. We present here the crystal structure of LOR_107, representing the first PL24 family structure. We found that LOR_107 adopts a seven-bladed β-propeller fold with a deep canyon on one side of the protein. Comparative sequence analysis revealed a cluster of conserved residues within this canyon, and site-directed mutagenesis disclosed several residues essential for catalysis. We also found that LOR_107 uses the His/Tyr catalytic mechanism, common to several PL families. We captured a tetrasaccharide substrate in the structures of two inactive mutants, which indicated a two-step binding event, with the first substrate interaction near the top of the canyon coordinated by Arg 320 , followed by sliding of the substrate into the canyon toward the active-site residues. Surprisingly, the LOR_107 structure was very similar to that of the PL25 family PLSV_3936, despite only ∼14% sequence identity between the two enzymes. On the basis of our structural and mutational analyses, we propose a catalytic mechanism for LOR_107 that differs from the typical His/Tyr mechanism.


    Organizational Affiliation

    the Department of Biochemistry, McGill University, Montreal, Quebec H3G 0B1, Canada.



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Short ulvan lyase
A, B
506Alteromonas sp. LORMutation(s): 1 
Gene Names: LOR_107
EC: 4.2.2
Find proteins for A0A109PTH9 (Alteromonas sp. (strain LOR))
Go to UniProtKB:  A0A109PTH9
Small Molecules
Ligands 6 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
83Y
Query on 83Y

Download CCD File 
A, B
6-deoxy-3-O-sulfo-alpha-L-mannopyranose
C6 H12 O8 S
PHTKRPBOKDCSPW-HGVZOGFYSA-N
 Ligand Interaction
GCB
Query on GCB

Download CCD File 
A, B
D-SACCHARIC ACID 1,5-LACTONE
C6 H8 O7
YLKFQNUGXOLRNI-QDQPNEQZSA-N
 Ligand Interaction
GCD
Query on GCD

Download CCD File 
A, B
4,5-DEHYDRO-D-GLUCURONIC ACID
C6 H8 O6
IAKKJSVSFCTLRY-YKKSOZKNSA-N
 Ligand Interaction
SO4
Query on SO4

Download CCD File 
A, B
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
GOL
Query on GOL

Download CCD File 
A, B
GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
CA
Query on CA

Download CCD File 
A, B
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.21 Å
  • R-Value Free: 0.255 
  • R-Value Work: 0.204 
  • R-Value Observed: 0.205 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 83.05α = 90
b = 120.959β = 90
c = 127.221γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
XDSdata scaling
Cootmodel building
PHASERphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2018-02-07
    Type: Initial release
  • Version 1.1: 2018-02-14
    Changes: Database references
  • Version 1.2: 2018-05-02
    Changes: Data collection, Database references
  • Version 1.3: 2019-04-24
    Changes: Author supporting evidence, Data collection