diff --git a/modelbuilder.py b/modelbuilder.py
index 3b7c93c..dd405d3 100644
--- a/modelbuilder.py
+++ b/modelbuilder.py
@@ -18,6 +18,7 @@ from build_modeller import PDBModeler
 from modeller import ModellerError
 import pymol
 from typing import Dict
+from Bio.SeqRecord import SeqRecord
 
 @dataclass
 class PDBAlign:
@@ -118,7 +119,7 @@ class LoopModelBuilder:
             split_dict[j]=fn.read_text()
         return split_dict
 
-    def model_missing_loops(self, typestr:str = 'refine.very_fast') -> dict:
+    def model_missing_loops(self, typestr:str = 'refine.very_fast', buildnumber: str = 1) -> dict:
         mc_dict = {}
         if not self.missing_info:
             self.logger.info(f'No missing residues found in {self.pdb_file}. Skipping model_missing_loops.')
@@ -126,42 +127,37 @@ class LoopModelBuilder:
         for mc in self.missing_info:
             out_file = f'{self.pdb_id}_{mc}.pdb'
             self.analyzer_instance.split_chain(mc).to_pdb(out_file) # get misschain pdb file
-            mc_fasta = self.analyzer_instance.filter_sequences(mc) # get misschain fasta file
-            if len(mc_fasta) == 1:
-                mc_fasta = mc_fasta[0]
-                out_fasta_file = Path(f'{self.analyzer_instance.pid}_{mc}.fasta')
-                self.analyzer_instance.write_seq_to_fasta_single_line(mc_fasta, out_fasta_file)
-                self.logger.info(f'>{mc_fasta.description}')
-                self.logger.info(mc_fasta.seq)
-                modeller = PDBModeler(self.pdb_file, out_fasta_file, Path('.'), mc, 1, typestr)
-                try:
-                    modeller_results = modeller.make_model()
-                except ModellerError as mod_err:
-                    self.logger.info(f'Failed to build model for chain {mc}')
-                    self.logger.info(f'No loops detected in {out_fasta_file.name}')
-                    self.logger.info(f'may pdb file sequence is not correct')
-                    self.logger.error(f'Modeller error for chain {mc}: {mod_err}')
-                    continue
-                except Exception as e:
-                    self.logger.error(f'Unexpected error in model_missing_loops: {e}')
-                self.logger.info(f'Model files: {[file.name for file in modeller_results]}')
-                # change id to original
-                for i in modeller_results:
-                    manalyzer = PDBAnalyzer(i)
-                    manalyzer.change_chain_identifier('A', mc, split=False).to_pdb(i)
-                if len(modeller_results) == 1:
-                    # use pymol to align
-                    aligner = PDBAlign(self.pdb_file, modeller_results[0],Path(f'{self.analyzer_instance.pid}_merge_model.pdb'))
-                    pdbstr = aligner.align()
-                    mc_dict[mc] = pdbstr
-                    return mc_dict
-                else:
-                    self.logger.warning('more than one model file, please set num_loop to 1')
-            elif len(mc_fasta) == 0:
-                self.logger.warning(f'No chain {mc} found in PDB fasta file. Skipping chain {mc}.')
+            mc_fasta = self.analyzer_instance.find_most_similar(self.sequences[mc]) # get misschain fasta file
+            mc_fasta_record = SeqRecord(mc_fasta, id=f'{mc}', description=f'{self.pdb_id}|{mc}')
+            out_fasta_file = Path(f'{self.analyzer_instance.pid}_{mc}.fasta')
+            self.analyzer_instance.write_seq_to_fasta_single_line(mc_fasta_record, out_fasta_file)
+            self.logger.info(f'>{self.pdb_id}|{mc}|{self.missing_info[mc]}|{len(mc_fasta)}')
+            self.logger.info(mc_fasta)
+            modeller = PDBModeler(self.pdb_file, out_fasta_file, Path(f'./{self.pdb_id}modellerfix_{mc}'), mc, buildnumber, typestr)
+            try:
+                modeller_results = modeller.make_model()
+            except ModellerError as mod_err:
+                self.logger.info(f'Failed to build model for chain {mc}')
+                self.logger.info(f'No loops detected in {out_fasta_file.name}')
+                self.logger.info(f'may pdb file sequence is not correct')
+                self.logger.error(f'Modeller error for chain {mc}: {mod_err}')
                 continue
+            except Exception as e:
+                self.logger.error(f'Unexpected error in model_missing_loops: {e}')
+            self.logger.info(f'Model files: {[file.name for file in modeller_results]}')
+            # change id to original
+            for i in modeller_results:
+                manalyzer = PDBAnalyzer(i)
+                manalyzer.change_chain_identifier('A', mc, split=False).to_pdb(i)
+            if len(modeller_results) == 1:
+                # use pymol to align
+                aligner = PDBAlign(self.pdb_file, modeller_results[0],Path(f'{self.analyzer_instance.pid}_merge_model.pdb'))
+                pdbstr = aligner.align()
+                mc_dict[mc] = pdbstr
+                return mc_dict
             else:
-                raise ValueError(f'only can fix one chain content: {mc_fasta}')
+                self.logger.warning('more than one model file, please set num_loop to 1')
+        return mc_dict
             
     def run(self, typestr:str = 'refine.very_fast'):
         split_dict = self.split_all_chains()