Answer:


In the table you see for each pair of amino acids the exact Cα-Cα distance.

   1 THR  (   1 ) A      CA  -   47 LYS  (   1 ) A      CA      1.394 Terminus
   2 THR  (   2 ) A      CA  -   48 SER  (   2 ) A      CA      0.443
   3 CYS  (   3 ) A      CA  -   49 CYS  (   3 ) A      CA      1.039
   4 CYS  (   4 ) A      CA  -   50 CYS  (   4 ) A      CA      0.573
   5 PRO  (   5 ) A      CA  -   51 PRO  (   5 ) A      CA      0.115
   6 SER  (   6 ) A      CA  -   52 ASN  (   6 ) A      CA      0.606
   7 ILE  (   7 ) A      CA  -   53 THR  (   7 ) A      CA      0.844
   8 VAL  (   8 ) A      CA  -   54 THR  (   8 ) A      CA      0.697
   9 ALA  (   9 ) A      CA  -   55 GLY  (   9 ) A      CA      0.377
  10 ARG  (  10 ) A      CA  -   56 ARG  (  10 ) A      CA      0.497
  11 SER  (  11 ) A      CA  -   57 ASN  (  11 ) A      CA      0.629
  12 ASN  (  12 ) A      CA  -   58 ILE  (  12 ) A      CA      0.488
  13 PHE  (  13 ) A      CA  -   59 TYR  (  13 ) A      CA      0.689
  14 ASN  (  14 ) A      CA  -   60 ASN  (  14 ) A      CA      0.803
  15 VAL  (  15 ) A      CA  -   61 ALA  (  15 ) A      CA      0.480
  16 CYS  (  16 ) A      CA  -   62 CYS  (  16 ) A      CA      0.440
  17 ARG  (  17 ) A      CA  -   63 ARG  (  17 ) A      CA      0.582
  18 LEU  (  18 ) A      CA  -   64 LEU  (  18 ) A      CA      1.216
  18 LEU  (  18 ) A      CA  -   65 THR  (  19 ) A      CA      2.693 ***
  19 PRO  (  19 ) A      CA  -   65 THR  (  19 ) A      CA      2.036 *** Pro
  19 PRO  (  19 ) A      CA  -   66 GLY  (  20 ) A      CA      2.235 *** Pro Gly
  20 GLY  (  20 ) A      CA  -   66 GLY  (  20 ) A      CA      1.687 *** (Both Gly)
  21 THR  (  21 ) A      CA  -   67 ALA  (  21 ) A      CA      1.329 ***
  21 THR  (  21 ) A      CA  -   68 PRO  (  22 ) A      CA      2.736 *** Pro
  22 PRO  (  22 ) A      CA  -   68 PRO  (  22 ) A      CA      1.520 *** (both Pro)
  22 PRO  (  22 ) A      CA  -   69 ARG  (  23 ) A      CA      2.760 *** Pro
  23 GLU  (  23 ) A      CA  -   69 ARG  (  23 ) A      CA      1.142
  24 ALA  (  24 ) A      CA  -   70 PRO  (  24 ) A      CA      0.877
  25 ILE  (  25 ) A      CA  -   71 THR  (  25 ) A      CA      0.872
  26 CYS  (  26 ) A      CA  -   72 CYS  (  26 ) A      CA      0.574
  27 ALA  (  27 ) A      CA  -   73 ALA  (  27 ) A      CA      0.531
  28 THR  (  28 ) A      CA  -   74 LYS  (  28 ) A      CA      0.614
  29 TYR  (  29 ) A      CA  -   75 LEU  (  29 ) A      CA      0.619
  30 THR  (  30 ) A      CA  -   76 SER  (  30 ) A      CA      0.451
  31 GLY  (  31 ) A      CA  -   77 GLY  (  31 ) A      CA      0.668
  32 CYS  (  32 ) A      CA  -   78 CYS  (  32 ) A      CA      0.711
  33 ILE  (  33 ) A      CA  -   79 LYS  (  33 ) A      CA      0.744
  34 ILE  (  34 ) A      CA  -   80 ILE  (  34 ) A      CA      0.885
  35 ILE  (  35 ) A      CA  -   81 ILE  (  35 ) A      CA      0.838
  36 PRO  (  36 ) A      CA  -   82 SER  (  36 ) A      CA      1.827 *** Pro
  37 GLY  (  37 ) A      CA  -   82 SER  (  36 ) A      CA      2.075 *** Gly
  37 GLY  (  37 ) A      CA  -   83 GLY  (  37 ) A      CA      1.941 *** (Both Gly)
  38 ALA  (  38 ) A      CA  -   84 SER  (  38 ) A      CA      1.377 ***
  39 THR  (  39 ) A      CA  -   85 THR  (  39 ) A      CA      1.600 ***
  40 CYS  (  40 ) A      CA  -   86 CYS  (  40 ) A      CA      0.383
  41 PRO  (  41 ) A      CA  -   87 PRO  (  41 ) A      CA      0.390
  42 GLY  (  42 ) A      CA  -   88 SER  (  42 ) A      CA      0.314
  43 ASP  (  43 ) A      CA  -   89 ASP  (  43 ) A      CA      0.245
  44 TYR  (  44 ) A      CA  -   90 TYR  (  44 ) A      CA      0.399
  45 ALA  (  45 ) A      CA  -   91 PRO  (  45 ) A      CA      1.320
  46 ASN  (  46 ) A      CA  -   92 LYS  (  46 ) A      CA      1.747 Terminus

The termini differ much, because they can, they don't need to compromise at one side. Furthermore, the number of glycines and prolines that are either present or mutated in or out is suspiciously high in the loops that differ most.

Obviously, this is not exam-material. I just hope you grasp the concept that there are many reasons for making errors in homology models!