[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[modeller_usage] Regarding BLOSUM MATRICES & MODELLER ALIGNMENT



Dear Modellers,
I found some interesting results today.Though some of these were much discussed by Sadowsky in some articles since 2007,
But still check these out.

Target1
		                           molpdf	DOPE	        Z-Score	        GDT-TS	GDT-HA TM-Score	RMSD
2P31 Modeling Scores	BLOSUM50	924.97821	-19218.93945	-1.37493	89.634	76.22	0.917	0.844
	                BLOSUM62	924.97821	-19218.93945	-1.37493	89.634	76.22	0.917	0.844
2I3Y Modeling Scores	BLOSUM50	1027.70447	-18048.86914	-0.89869	79.268	57.165	0.873	1.568
                 	BLOSUM62	1027.70447	-18048.86914	-0.89869	79.268	57.165	0.873	1.568
2OBI Modeling Scores	BLOSUM50	1019.33649	-18713.56836	-1.16924	85.671	68.293	0.914	1.325
                 	BLOSUM62	993.73724	-14176.32422	 0.67751	39.482	15.244	0.586	.3.727



Target2

 2RIR	           molpdf	    DOPE	Z-Score	         GDT-TS	GDT-HA	TM-Score RMSD	
BLOSUM50	1528.87537	-34527.82422	-1.28434Complete89.568	68.255	0.973	1.037	
                                 			Domain1	96.507	83.824	0.972	0.77	
                                  			Domain2	99.823	89.184	0.985	0.553	
BLOSUM62	1528.87537	-34527.82422	-1.28434Complete89.568	68.255	0.973	1.037	
                                  			Domain1	96.507	83.824	0.972	0.77	
                                			Domain2	99.823	89.184	0.985	0.553	
									
2CUK	           molpdf	     DOPE	Z-Score		GDT-TS	GDT-HA	TM-Score RMSD	
BLOSUM50	1942.12292	-25812.05664	0.82958	Complete17.356	5.665	0.382	4.106	
                                  			Domain1	25.735	13.419	0.361	2.613	
                                			Domain2	30.674	13.121	0.411	2.93	
BLOSUM62	2036.98694	-26931.20703	0.55814	Complete16.277	5.036	0.348	4.12	
                                      			Domain1	15.625	6.066	0.256	2.82	
                                      			Domain2	34.752	15.426	0.456	2.747	



Target3
							
	          molpdf	    DOPE	Z-Score	GDT-TS	GDT-HA	TM-Score RMSD
2Q7B							
BLOSUM50	1212.10278	-16748.72461	-0.8108	 81.414	61.184	0.879	1.283
BLOSUM62	1175.47266	-17014.03516	-0.92678 87.336	66.118	0.925	1.227
2OH1							
BLOSUM50	1450.15808	-12735.95215	0.94347	 28.947	13.487	0.426	2.797
BLOSUM62	1007.18695	-15380.72852	-0.21275 56.743	33.388	0.73	2.367
1S60							
BLOSUM50	836.13391	-13656.52148	0.54102	55.428	35.526	0.674	1.961
BLOSUM62	1039.06799	-13509.62109	0.60524	57.237	37.500	0.698	2.002
							

So You might have realized there is a huge differences in the alignments. Sometime same and different for quite others. 
Even the accuracies, molpdf and other scores are different, when it comes to the models created on basis of only this factor keeping all others constant.
Even the accuracy of MODELLER single template models also gets inferior sometimes. 
So I infer that it seems 
1. MODELLER pairwise algorithm is not purely biased on local fold alignment, though it uses Smith Waterman based align2d.py module. 
2. All algorithmic alignments are almost similar with minimal differences for easy targets. However, when the PDB profile is employed for Pairwise alignments through any BLOSUM matrix, the case may differ much when the employed template shares a negligible sequence identity to the target.
3. Will these results be still different when BLOSUM80 is used for these targets the same way?

I hope a good explanatory reply from Sir Ben Webb.
Thanks
Ashish 

Ashish Runthala,
Lecturer, Structural Biology Cell,
Biological Sciences Group,
BITS, Pilani
Rajasthan, INDIA