diff --git a/src/CommandDeclarations.h b/src/CommandDeclarations.h
index 2d6a5b241..a5b38820a 100644
--- a/src/CommandDeclarations.h
+++ b/src/CommandDeclarations.h
@@ -56,6 +56,7 @@ extern int lca(int argc, const char **argv, const Command& command);
 extern int profile2pssm(int argc, const char **argv, const Command& command);
 extern int profile2cs(int argc, const char **argv, const Command& command);
 extern int offsetalignment(int argc, const char **argv, const Command& command);
+extern int proteinaln2nucl(int argc, const char **argv, const Command& command);
 extern int apply(int argc, const char **argv, const Command& command);
 extern int shellcompletion(int argc, const char **argv, const Command& command);
 
diff --git a/src/mmseqs.cpp b/src/mmseqs.cpp
index 7a1d6fe6f..63376cc82 100644
--- a/src/mmseqs.cpp
+++ b/src/mmseqs.cpp
@@ -253,6 +253,12 @@ std::vector<struct Command> commands = {
                 "Martin Steinegger <martin.steinegger@mpibpc.mpg.de>",
                 "<i:queryDB> <i:targetDB> <i:alnDB> <o:alnDB>",
                 CITATION_MMSEQS2},
+        {"proteinaln2nucl",          proteinaln2nucl,          &par.onlythreads,            COMMAND_DB,
+                "Map protein alignment to nucleotide alignment",
+                NULL,
+                "Martin Steinegger <martin.steinegger@mpibpc.mpg.de> ",
+                "<i:alnDB> <o:alnDB>",
+                CITATION_MMSEQS2},
         {"tsv2db",               tsv2db,               &par.tsv2db,               COMMAND_DB,
                 "Turns a TSV file into a MMseqs database",
                 NULL,
diff --git a/src/util/CMakeLists.txt b/src/util/CMakeLists.txt
index de1a118a5..953701d08 100644
--- a/src/util/CMakeLists.txt
+++ b/src/util/CMakeLists.txt
@@ -42,5 +42,6 @@ set(util_source_files
         util/swapresults.cpp
         util/translatenucs.cpp
         util/tsv2db.cpp
+        util/proteinaln2nucl.cpp
         PARENT_SCOPE
         )
diff --git a/src/util/proteinaln2nucl.cpp b/src/util/proteinaln2nucl.cpp
new file mode 100644
index 000000000..df4fe291b
--- /dev/null
+++ b/src/util/proteinaln2nucl.cpp
@@ -0,0 +1,99 @@
+//
+// Created by mad on 11/28/17.
+//
+#include <string>
+#include <vector>
+#include <fstream>
+#include <FileUtil.h>
+#include <Orf.h>
+
+#include "Alignment.h"
+#include "Util.h"
+#include "Parameters.h"
+#include "Matcher.h"
+#include "PrefilteringIndexReader.h"
+
+#include "Debug.h"
+#include "DBReader.h"
+#include "DBWriter.h"
+
+#ifdef OPENMP
+#include <omp.h>
+#endif
+
+
+int proteinaln2nucl(int argc, const char **argv, const Command &command) {
+    Parameters &par = Parameters::getInstance();
+    par.parseParameters(argc, argv, command, 2);
+
+    Debug(Debug::INFO) << "Alignment database: " << par.db1 << "\n";
+    DBReader<unsigned int> alnDbr(par.db1.c_str(), par.db1Index.c_str());
+    alnDbr.open(DBReader<unsigned int>::LINEAR_ACCCESS);
+
+    DBWriter resultWriter(par.db2.c_str(), par.db2Index.c_str(), par.threads);
+    resultWriter.open();
+    Debug(Debug::INFO) << "Start writing file to " << par.db2 << "\n";
+
+#pragma omp parallel for schedule(dynamic, 10)
+    for (size_t i = 0; i < alnDbr.getSize(); i++) {
+        unsigned int thread_idx = 0;
+#ifdef OPENMP
+        thread_idx = static_cast<unsigned int>(omp_get_thread_num());
+#endif
+
+        unsigned int alnKey = alnDbr.getDbKey(i);
+        char *data = alnDbr.getData(i);
+
+        std::string querySeq;
+
+        char buffer[1024];
+        std::string ss;
+        ss.reserve(1024);
+
+
+        std::vector<Matcher::result_t> results = Matcher::readAlignmentResults(data, true);
+        for (size_t j = 0; j < results.size(); j++) {
+            Matcher::result_t &res = results[j];
+            bool hasBacktrace = (res.backtrace.size() > 0);
+            std::string newBacktrace;
+            newBacktrace.reserve(1024);
+            res.dbStartPos = res.dbStartPos*3;
+            res.dbEndPos   = res.dbEndPos*3;
+            res.dbLen      = res.dbLen*3;
+            res.qStartPos  = res.qStartPos*3;
+            res.qEndPos    = res.qEndPos*3;
+            res.qLen       = res.qLen*3;
+            for (size_t pos = 0; pos < res.backtrace.size(); pos++) {
+                int cnt=0;
+                if(isdigit(res.backtrace[pos])){
+                    cnt += Util::fast_atoi<int>(res.backtrace.c_str()+pos);
+                    while(isdigit(res.backtrace[pos])){
+                        pos++;
+                    }
+                }
+                switch(res.backtrace[pos]){
+                    case 'M':
+                    case 'D':
+                    case 'I':
+                        newBacktrace.append(std::string(cnt*3, res.backtrace[pos]));
+                        break;
+
+                }
+
+            }
+            res.backtrace = newBacktrace;
+
+            size_t len = Matcher::resultToBuffer(buffer, res, hasBacktrace, true);
+            ss.append(buffer, len);
+        }
+
+        resultWriter.writeData(ss.c_str(), ss.length(), alnKey, thread_idx);
+        ss.clear();
+    }
+    alnDbr.close();
+    resultWriter.close();
+    Debug(Debug::INFO) << "Done." << "\n";
+
+    return EXIT_SUCCESS;
+}
+