""" A module that works with ProtTrans models. Functions were adapted from ProtTrans authors' Google Colab notebook """ from transformers import T5EncoderModel, T5Tokenizer import torch import os import sys from hashlib import sha256 from transformers import logging as hf_logging hf_logging.set_verbosity_error() hf_logging.disable_progress_bar() def get_pretrained_model(model_path): """ Fetches the model accordingly to the model_path model_path - STRING that identifies the model to fetch Returns model. """ device = torch.device('cuda:0' if torch.cuda.is_available() else 'cpu') if(os.path.exists(model_path+'/pytorch_model.bin') and os.path.exists(model_path+'/config.json')): model = T5EncoderModel.from_pretrained(model_path+'/pytorch_model.bin', config=model_path+'/config.json') else: model = T5EncoderModel.from_pretrained(model_path) model = model.to(device) model = model.eval() return model def get_tokenizer(model_path): """ Fetches the tokenizer accordingly to the model_path model_path - STRING that identifies the model whose tokenizer should be fetched returns tokenizer """ tokenizer = T5Tokenizer.from_pretrained(model_path, do_lower_case=False) return tokenizer def load_model_and_tokenizer(pt_dir, pt_server_path): """ Load ProtTrans model and tokenizer. pt_dir - STRING to determine the path to the directory with ProtTrans "pytorch_model.bin" file pt_server_path - STRING of the path to ProtTrans model in its server returns (ProtT5-XL model, tokenizer) """ if(not os.path.exists(f"{pt_dir}/")): os.system(f"mkdir -p {pt_dir}/") if(os.path.isfile(f"{pt_dir}/pytorch_model.bin")): # Only loading the model model = get_pretrained_model(pt_dir) else: # Downloading and saving the model model = get_pretrained_model(pt_server_path) model.save_pretrained(pt_dir) if(os.path.isfile(f"{pt_dir}/tokenizer_config.json")): # Only loading the tokenizer tokenizer = get_tokenizer(pt_dir) else: # Downloading and saving the tokenizer tokenizer = get_tokenizer(pt_server_path) tokenizer.save_pretrained(pt_dir) return (model, tokenizer) def process_FASTA(fasta_path, split_char="!", id_field=0): """ Reads in fasta file containing multiple sequences. Split_char and id_field allow to control identifier extraction from header. E.g.: set split_char="|" and id_field=1 for SwissProt/UniProt Headers. Returns dictionary holding multiple sequences or only single sequence, depending on input file. """ seqs = dict() orig_seq_headers = dict() orig_seqs = dict() with open(fasta_path, 'r') as fasta_f: for line in fasta_f: if line.startswith('>'): uniprot_id = line.replace('>', '').strip().split(split_char)[id_field] uniprot_id = uniprot_id.replace("/", "_").replace(".", "_") seqs[uniprot_id] = '' orig_seq_headers[uniprot_id] = line.replace('>', '').strip() orig_seqs[uniprot_id] = '' else: orig_seqs[uniprot_id] += line.strip() seq = ''.join(line.split()).upper().replace("-", "") seq = seq.replace('U','X').replace('Z', 'X').replace('O', 'X') seqs[uniprot_id] += seq example_id = next(iter(seqs)) return (seqs, orig_seq_headers, orig_seqs) def get_embeddings(model, tokenizer, seqs, per_residue, per_protein, max_residues=4000, # number of cumulative residues per batch max_seq_len=2000, # max length after which we switch to single-sequence processing to avoid OOM max_batch=100 # max number of sequences per single batch ): """ Generation of embeddings via batch-processing. per_residue indicates that embeddings for each residue in a protein should be returned. per_protein indicates that embeddings for a whole protein should be returned (average-pooling). returns results depending on the option in the input. """ device = torch.device('cuda:0' if torch.cuda.is_available() else 'cpu') results = {'per_res_representations': dict(), 'mean_representations': dict()} seq_dict = sorted(seqs.items(), key=lambda kv: len(seqs[kv[0]]), reverse=True) batch = list() for seq_idx, (pdb_id, seq) in enumerate(seq_dict, 1): seq_len = len(seq) seq = ' '.join(list(seq)) batch.append((pdb_id, seq, seq_len)) n_res_batch = sum([s_len for _, _, s_len in batch]) + seq_len if (len(batch) >= max_batch) or (n_res_batch >= max_residues) or (seq_idx == len(seq_dict)) or (seq_len > max_seq_len): pdb_ids, seqs, seq_lens = zip(*batch) batch = list() token_encoding = tokenizer(seqs, add_special_tokens=True, padding='longest') input_ids = torch.tensor(token_encoding['input_ids']).to(device) attention_mask = torch.tensor( token_encoding['attention_mask']).to(device) try: with torch.no_grad(): embedding_repr = model(input_ids, attention_mask=attention_mask) except RuntimeError: print(f"{sys.argv[0]}: runtime error generating embedding for {pdb_id} (L={seq_len}). "+\ f"Try lowering batch size. If single sequence processing does not work, you need "+\ f"more vRAM to process your protein.", file=sys.stderr) continue for batch_idx, identifier in enumerate(pdb_ids): s_len = seq_lens[batch_idx] emb = embedding_repr.last_hidden_state[batch_idx,:s_len] if per_residue: results["per_res_representations"][identifier] = \ emb.detach().cpu().numpy().squeeze() if per_protein: protein_emb = emb.mean(dim=0) results["mean_representations"][identifier] = \ protein_emb.detach().cpu().numpy().squeeze() return results def save_embeddings(sequences, embeddings, embeddings_directory, embedding_type="mean"): """ Saving embeddings to PT files for later use. sequences - DICT with sequence ids as keys and sequences themselves as values embeddings - DICT with generated embeddings for each sequence embeddings_directory - STRING that determines the path to directory for embeddings embedding_type - STRING that determines, which type of embeddings to save """ embedding_type_key = embedding_type+"_representations" for seq_id in list(sequences.keys()): seq_data = {"label": seq_id} if(seq_id in embeddings[embedding_type_key].keys()): seq_data["sequence"] = sequences[seq_id] seq_data[embedding_type_key] = torch.from_numpy( embeddings[embedding_type_key][seq_id]) seq_code = sha256(sequences[seq_id].encode('utf-8')).hexdigest() torch.save(seq_data, f"{embeddings_directory}/{embedding_type}_{seq_code}.pt") def print_embeddings_generation_stats(iteration, portion_size, embeddings, seqs_wo_emb, start_time, end_time): """ Printing embeddings generation statistics. iteration - INT index of the iteration (indexing from zero) portion_size - INT size of the processed portion embeddings - DICT with keys 'mean_representations' and 'per_res_representations' seqs_wo_emb - DICT with a portion of sequence ids as keys and amino acid sequences as values start_time - datetime object of the beginning of embeddings' generation end_time - datetime object of the end of embeddings' generation """ print(f"Portion {int(iteration/portion_size)+1}.", file=sys.stderr) print(f"{len(embeddings['mean_representations'].keys())}/{len(list(seqs_wo_emb.keys()))}: "+\ "sequences with generated mean embeddings", file=sys.stderr) print(f"{len(embeddings['per_res_representations'].keys())}/{len(list(seqs_wo_emb.keys()))}: "+\ "sequences with generated per-residue embeddings", file=sys.stderr) print("%s: time to generate embeddings" % (end_time - start_time), file=sys.stderr) print("%s: time to generate embeddings per protein" % ((end_time - \ start_time)/len(embeddings["mean_representations"])), file=sys.stderr)