Conserved Protein Domain Family
CBM20_alpha_MTH

?
cd05810: CBM20_alpha_MTH 
Glucan 1,4-alpha-maltotetraohydrolase (alpha-MTH), C-terminal CBM20 (carbohydrate-binding module, family 20) domain. Alpha-MTH, also known as maltotetraose-forming exo-amylase or G4-amylase, is an exo-amylase found in bacteria that degrades starch from its non-reducing end. Most alpha-MTHs have, in addition to the C-terminal CBM20 domain, an N-terminal glycosyl hydrolase family 13 catalytic domain. The CBM20 domain is found in a large number of starch degrading enzymes including alpha-amylase, beta-amylase, glucoamylase, and CGTase (cyclodextrin glucanotransferase). CBM20 is also present in proteins that have a regulatory role in starch metabolism in plants (e.g. alpha-amylase) or glycogen metabolism in mammals (e.g. laforin). CBM20 folds as an antiparallel beta-barrel structure with two starch binding sites. These two sites are thought to differ functionally with site 1 acting as the initial starch recognition site and site 2 involved in the specific recognition of appropriate regions of starch.
Statistics
?
PSSM-Id: 99885
View PSSM: cd05810
Aligned: 13 rows
Threshold Bit Score: 150.251
Threshold Setting Gi: 126659022
Created: 10-Sep-2007
Updated: 17-Jan-2013
Structure
?
Aligned Rows:
 
starch-bindingstarch-binding
Feature 1:starch-binding site 1 [chemical binding site]
Evidence:
  • Comment:Based on the binding of substrates to the starch binding site 1 of other family members.
  • Comment:Site 1 is small relative to site 2 and exhibits minimal structural changes upon ligand binding. It acts as an initial starch recognition site.
  • Citation:PMID 9195884
  • Citation:PMID 8672460

Sequence Alignment
?
Format: Row Display: Color Bits: Type Selection:
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
Feature 1                                     #                               #               ## 
gi 151013    451 VSVSFRCDNGATQMGDSVYAVGNVSQLGNWSPAAALRLTDtsgYPTWKGSIALPAGQNEEWKCLIRNEanat-qvrQWQG 529
gi 90022580  467 VETTFSCSNGSTYWGQSVYVIGNQEELGNWNPAHAVKLDAs-aYPTWTGTIELTQNTDVEWKCLKRDEqtps-ngvVWQG 544
gi 149375630 473 ATVTFQCQNGTTTMGQSVYVTGNDSALGNWSPADAVKLDPt-aYPTWTGSIDLPAQTSIEWKCLKRSEtdpg-aqqQWQS 550
gi 115376651 561 VAVTFTCNNGQTVAGQSVYVVGSLAALGTWAPASAIKLTPs-sYPTWTGTVTLPASTGLEWKCLKRNEtdat-qgvQWQG 638
gi 91793156  534 VAVTFNCNNGVTYAGQDVYVVGNQANLGNWNTAAAIKLSPt-gYPSWSGTINLPMSKAIEWKCIKKSAte-----vVWQG 607
gi 83646851  484 VDVSFTCDNGQTQWGQSVYAVGDLPELGGWSPAGAVKLEPt-aYPVWSGVISVPMGTQIEWKCLKRDEnnpg-agiEWQP 561
gi 126659022 576 VDVSFSCQNGHTELGTSVYVAGNIKELGNWSVKDASQKLAptdYPTWTGSLTLPAKTNLEWKCVKALEssl--kitQWQG 653
gi 90019963  549 ELVQFNCDNGFTQLGQSVYVVGSSPELGSWSVENAVLLAPv-nYPLWSTTISIPINTQMEWKCVKRDEqnpa-vnvEWQA 626
gi 113760    455 VNVNFRCDNGVTQMGDSVYAVGNVSQLGNWSPASAVRLTDtssYPTWKGSIALPDGQNVEWKCLIRNEadat-lvrQWQS 533
gi 116048    560 QSINFTCNNGYTISGQSVYIIGNIPQLGGWDLTKAVKISPt-qYPQWSASLELPSDLNVEWKCVKRNEtnpt-anvEWQS 637
gi 153217603 562 KSVTFTCYNGYTNLGQSVYAVGSVAQLGNWMPVDAVKLAPt-qYPTWSATIRVPATQSIEWKCLKRNEtnpa-lnvVWQS 639
gi 87122266  473 AFISFSCNNASTYLGQSVYVVGDIAALGNWQISQAIKLDAa-nYPNWQASISVPANTQVQWKCVKREEqdas-agvEWQA 550
gi 50978534  865 VWATFSCENATTTFGQSVYVVGNVPQLGNWSPADAVKLEPsayPTWTGVVRNLPPSSTVEWKCIKRQEaglpntadAWEP 944
                         90       100
                 ....*....|....*....|....*.
Feature 1               #                  
gi 151013    530 G-----ANNSL-TPSe--GATTVGRL 547
gi 90022580  545 G-----ANNQFnTGTt--NAYPTGSF 563
gi 149375630 551 G-----GNNQVqTGGegtSSSTSGSF 571
gi 115376651 639 G-----GNNALtTPAs-gTASASASF 658
gi 91793156  608 G-----GNNTYtTPSs-gVGSTSASF 627
gi 83646851  562 G-----SNTVF-NSDl--INATRGGW 579
gi 126659022 654 NtktksGNNEVfVGNs--NVSVTGGF 677
gi 90019963  627 G-----ANNVLdTGV---TAFTQASF 644
gi 113760    534 G-----GNNQV-QAAa--GASTSGSF 551
gi 116048    638 G-----ANNQF-NSNd--TQTTNGSF 655
gi 153217603 640 G-----ANNQL-HSS---SSASQGSF 656
gi 87122266  551 G-----ANNQVtSGNlgqTVQSSGSF 571
gi 50978534  945 G-----GNNILsTPPsgsAGITTGAF 965

| Disclaimer | Privacy statement | Accessibility |
NCBI Home NCBI Search NCBI SiteMap